Colton: The Refconverter A for K-mount cameras came with a screw-in eyecup - if you can find one - that might increase its utility in your ergonomic circumstances. KEH has an Eyecup. I use one with my SuperPROGRAM and MZ-S from time to time, and even used it on my K-3 once. Very helpful for long lens tripod shots, which I do seated.
The Olympus
Vari-Magni OM also works. It is a bit more sophisticated (I used one for a while) and often less expensive NOS/NIB than a used Pentax A.
Last edited by monochrome; 02-11-2017 at 05:25 PM.