Errr.... yes!

Trouble is it's over two hundred miles each way, but in a Nissan Leaf the fuel cost should be zero.

Perhaps I'll have to arrange a trip by way of Welwyn Garden City and deliver it by hand.

If you can find a suitable silver one I'd be happy to purchase the black one in due course - an alternative to a direct swap?

I'm puzzled as to why the current UK store price for this lens is so high. The US price is $769, but the UK store price almost everywhere (ignoring the potentially dodgy Levaretech) is £829.

I know the UK GBP price digits often equals the US dollar digits, but $769 should come out close to £540, not more than £769. What's going on? The Japanese price is often under £500, so clearly this has to be grossly overpriced in the UK at the moment. Rip Off Britain is back (if it ever went away!)

I contacted Sigma directly regarding getting the mount on my 150-500 replaced.
Their reply directed me to http://www.sigma-imaging-uk.com/returns and to follow the instructions for sending it to them for the mount to be replaced. Apparently this will be done at no cost and they will contact me once received. But I am left to fork out £27.60 postage to get it to them though. Hardly no cost.

As I purchased from SRS, getting the lens to them to deal instead would incur an identical postage cost.

A well written appraisal. Well done.

Yes, but only for the K-1, K-3 II, K-S2 and K-S1 (the K-70 being compatible from the off) according to the report : https://www.pentaxuser.com/news/pentax-launch-hd-da-55-300mm-f-4-5-6-3-ed-plm-wr...

Ricoh have history of adding odd things to Pentax mounts, like the extra pin on their film camera lenses that caused them to become stuck on Pentax cameras! Perhaps this new lens gets stuck on older Pentax cameras by strong electromagnetism!

Isn't it easiest just to focus from the centre point and recompose? No faffing about pressing buttons required! That was the only option on all my film SLRs (centre prism.) And on cameras before those one had to guess or measure the distance! So thank goodness Pentax haven't put a joystick on the camera as from experience that's invariably the first thing to fail. Those that want joysticks can purchase inferior cameras that do have such things. I vowed never purchase such a thing again so should Pentax do that they'd loose my future custom. If a joystick's essential then perhaps an external one could be made available to plug in thus convert the camera to double up as a Playstation!
Sorry to sound harsh but I'd simply hate that to happen and the opposite viewpoint needs to be made.

Oh dear

It's OK, I know you posted tongue in cheek, but others may not realise that. Those others clearly include techmartpro whoever they are but suspect they should know better, being 'pro.'

Are you suggesting there isn't such a thing?
http://www.bdimitrov.de/kmp/teleconverters/F1.7X.html
They're relatively common but folk don't wish to part with them! One sold on eBay recently for £150. There's currently a couple listed in Germany but at over £250. I'd happily sell mine if the OP wishes to make an offer in that region, otherwise I'd prefer to keep it.