M42 + adaptor or SMC

Okay kind of following on from my last thread. So I have an S1a, this was my late great grandsfathers Its in great condition and works just fine. I had visions of bringing this old camera back to life after 20 odd years. With it he had a 50mm f2 and the 135mm 3.5. I've since added the 28mm f3.5 and the 35mm f3.5. Couple of things though, one is that I dont want to ruin the S1a and I spend alot of time outdoors in the elements and its just a matter of time before I drop it, scratch etc. The other is I have my ME super on the way. So I'm going to hang up my great grandfathers kit and just use the ME. What I'm not sure is whether to get an M42 to bayonet adaptor and continue using the 28mm and the 35mm I purchased or whether it would make more sense to sell them and replace them with the SMC versions. What other benefits are there other than not being restricted to stop down metering?

Okay may of gone on there a little but hope you get the jist of what I mean and your thoughts are appreciated.

You could happily use your existing lenses on the ME Super. The adapter effectively turns it into a screw thread camera and you can change lenses in the usual way. Apart from using stop-down metering there aren't any disadvantages really. The lenses you have are already very fine ones.

If buying lenses though you might as well have the SMC Pentax or SMC Pentax-M ones as they will be slightly faster to use and also there will be more adventurous designs available, such as the 50mm f1.2 and the various zooms.

Is the 'Pentax K Mount Adapter' in the shop here the one I'm after? if so says up to 28 days, how close to the mark is that, was hoping before xmas? Not finding anything genuine Pentax on the bay.

Pentax Adapter K should be available easily enough - try SRS

Ideal, cheers John.