Ricardo Miranda
Member
They sometimes appear on Ebay UK as for parts.I am currently looking for a scrap OM2sp to take apart and see how viable a on/off switch would be .
If you know street market sellers, ask around.
One might have a scrappy one.
This might help you: http://olympus.dementix.org/Hardware/PDFs/OM-2S_spt.pdf
If you don't know that website, here is the main page for all the service manuals: http://olympus.dementix.org/Hardware/olympus_hw.html
Have a good read!