and then I remembered!

oh if you just got here you missed the good part...

I'll start over:
Several months ago, after picking up two K-r bodies, I remembered just what using a penta-mirror viewfinder was like. (Hint: not good.) I sought options that would enable me to see well enough to focus manually, as at the time I owned several manual primes.  This was also the time when KatzEye bright focusing screens disappeared as the company dealt with financial issues, so the best-known option was unavailable.

So off I went to the search engines, seeking bargain alternatives.  I found a mystery auction dealer that sold one-fits-all Pentax screens for under $20 and ordered a split screen fresnel collared screen.  It took a while to get here but i jumped in when it reached me.

only to find it didn't fit!
The screen was labeled for K-7 only but I was pretty sure it was not so exclusive.  The K-r swap was new to me though, and clearly it wasn't working - so I sought to return the screen for a refund.

only I never sent it back!
So here's where you came in: today I remembered it had not left my shelf.  I still have several manual focus lenses.. but now a K-s1 body makes use of them.  Could it be possible that the old cheap screen would fit the new camera?

yes it can.
So now the K-s1 has focus peaking And a more precise focus screen.  Test images show that it aligns just fine.
Overkill perhaps, but the screen is here anyway.. so why not?

One Last Piece

I had contemplated a final prime above 100mm to complete my set.  I sought something curious, but had no idea what it would be.  I knew it would not be a Pentax 150 or 200mm;  I had owned and sold one of each and did not miss them enough.

Then I saw this.

It's an old T-mount Vivitar preset, a 180mm f/3.5, that comes with a MD adapter but of course can use my K adapter.  It is small but Very dense at ~635g, apparently made by Tamron a long time ago.   It uses 58mm filters and hood that I already have for the 55-300.  It also looks like new despite being just a few years younger than me, introduced when Kennedy was President!  Soligor also made a 189/3.5, but it looks a lot different. 

So it fits well with current gear and fills the prime gap between 100 and 400mm with a unique instrument.  Why not bid?

My bid stood alone so it was a bargain that will arrive soon.  I look forward to giving it a try!