Hello,

I have several old mortise locks made by Penn Hardware probably around
1925 or so. They are all for interior doors and so either have
rudimentary skeleton key holes or thumb bolts. I have removed them from
the various doors in my apartment.

I want to open them up, take off all the layers of paint which have
accumulated on their external surfaces by soaking and scraping,
lubricate them, and reassemble them. I've been able to do this
successfully with three of them -- the ones with thumbscrews.

The ones with key holes are nearly identical, except that for some
reason, the "exterior plate" (I don't know what to call this, the piece
that is visible when the lock is installed and which has been painted
over a hundred times) is not screwed onto the casing, as is the case
with the others. Rather, in the place of screws are what looks like some
kind of bolts or nails -- there is no slot in the head. And on the
inside, the other end of these bolts have a weird sort of "plus"
engraved in them which extends across both the bolt and the casing, like
it was burned in while it was hot or something. Sorry if this
description is poor, I just don't know how else to say it.

So my question is, is there any way to remove something like that? And
if not, what is the best way to go about getting the paint off these
other cases?

Thanks for any help -- I appreciate it.

Ivan.