Trouble is I'll probably have kids at University around then. With the way funding is going I'll have nothing left for cameras for a very long time after that.

iso-propanol (IPA) is not anything like as bad as Methylated spirits (methanol).
Methanol is classed as Toxic and EH40 lists an exposure limit 5 times lower than that for IPA. (With it's lower volatility its actualyy considerable better than that suggests)

In addition IPA works much better! methanol is not miscible with most hydrocarbons, whilst IPA is miscible with all common solvents, and will disolve any traces of oils nicely.

I rather suspect that most 'lens cleaning fluid' sold is just IPA.

The mirrors on our spectroscopy instruments are typically cleaned with just a stream of distilled water, followed by a stream of IPA, being top silvered no contact with tissues etc can be accepted.

(Yes I'm also involved in optics & Science)

Mike

Indeed it wasn't, but apparently Cameraboy is also called Ian (at least according to his profile).

Welcome to the forum Ian, the easy use of old lenses is certainly one of the benefits of Pentax DSLRs.

Actually I'd make a point to always carry at least one spare memory card!
(And as Alan says make sure you leave it in the camera!)

If you have a reasonably Library nearby, you can usefully browse their photography / processing books. DSLRs are IMHO much more flexible than compacts a fairly quick flick through can introduce techniques to play with. Flickr has groups for just about any obscure technique it seems so you can read tips & see relevant photos there too. (Not all the photos phosted in a group are relevant though!)

As many posts above have said, play with the camera & take lots of pictures. I'd recommend trying the different manual settings individually to begin with (shutter speed, aperture, ISO, focus) The photos may not be brilliant, but you should learn more about the options.

Lens arrived today, Thanks Jon.

The adaptall mount had come loose in the post despite copious bubble-wrap (excellent packing) causing me some concern until I mounted it on the camera & found the A setting wasn't as far round as I had thought (so it wasn't jamming at all)

Optics look crystal clear, & as far as I can conveniently test indoors it all works perfectly perfect.

My wife hasn't even said a word about 'ANOTHER lens', but I'd better do the cooking tonight

If you want P-TTL have a look at Matt Miller's website
It has a table giving the features of all the current models & is generally rather good on explaining the options.

Apparently the Metz 36 AF-4 does have P-TTL & rear/second curtain modes. His link to Amazon sugests the price ($110) might be outside your range, going by the typical Tech convertion rate of $1=£1

If your lenses have no saperture ring you won't have any control of aperture with a K fit TC. IIRC you'll be left with both lenses wide open with the TC. You'll probably find cropping the image a better solution for the moment (which needn't cost anything). KA type TCs allow the camera to adjust the aperture of your lenses so get round this problem, but that makes them much more sort after (& more expensive)

With K fit lenses you will need to do both focus & aperture manually. You'll also need to enable the use of the aperture ring in one of the cameras menus, and ideally use stop down (green button) exposure metering.

If you want to get longer reach, with-out croping, I managed to get a Pentax F100-300 for under £50 - autofocus,auto aperture, & not a bad make - Perhaps you'll find something similar...

One of the main advantages of an external flash is the ability to use it off camera, changing the dirrection light comes from. Some use radio triggers to do this, another option is a wired connections as discussed here:
https://www.pentaxuser.com/forum/topic/cheap-ebay-off-camera-ttl-lead-24426#comm272348

The most flexible flashes use through the lens light metering (P-TTL for pentax DSLRs) using a breif preflash to get the right power output.

Other options you may want include:

Second curtain flash (flash fires at the end of a longer exposure)
Strobing (multiple lower power flashes)
Bounce/swivel - not too important if the flash if off camera as then you can aim the whole flash
Modeling light
High power output (Guide No.)
Adjustable power (I think all do but the degree of adjustment varies)
Auto zoom with focal length
Diffuser built in
....

Like many on the forum I grabbed the Pentax AF360 FGZ last year when Curries had it at under half price (I think the List price is £212!). For me P-TTL & second curtain were the features I particularly wanted.

I've got several older flashes for very little that I can use, but they require a lot more thought & restrict aperture choice (manual control). I've picked up some of these with reasonable guide numbers for under £5 (after checking the trigger voltage)

Pawel, I don't have anything to suggest in your price range, but knowing which features you want/need would help narrow down the options.

If you not after advanced features at all & only want a manual (or non TTL semi auto) flash, then there are many old units that would do the job - However you do need to check the trigger voltage with older flashes. Some can damage your camera (I've seen reports saying 24V and below should be safe, IIRC the current spec is 5V)

Looks like good choice of subject, having a suitable range of heights across the image.

It looks as if you might have missed out on a couple of budget macro solutions in your list. Reversing a lens (best with wide-normal primes) & stacking lenses (reversing a prime on the front of a longer lens). Adapters for both of these options are cheap, and stacking can be done with only gaffer tape or even just holding the lens in place.

Unfortunately I don't have a Pentax Macro (I've got a Cosina 100mm macro & somewhere an old 28mm macro) nor do I live anywhere near Swindon...

Good luck with the project.