Putting together a Stevens Marksman-12 and I'm old and can't use the standard Marksman sights and wondered if there was a Lyman type rear sight I could use. I do have a an old adjustable no-name tang sight I think I can make a mount that will go on the narrow metal section that fits in the stock. Is there a Lyman adjustable receiver mounted rear sight that might work on the Stevens Marksman and not block the hammer? This is not meant to be a collector or anything -- Just another little single shot for my Old Man's backyard target range. 

Thanks for any help,
Boomer