While cleaning my parent's house, we found a periscope that is in pretty good shape, but the glass and mirrors are fairly clouded. Does anyone know how to dismantle it or have any recommendations for cleaning it?

On one of the sides there is a stamp:
Periscope M5
MPLS HON REG CO
NO 18257 D.A.
1942

Not sure why you want to clean it but as an artifact it is more valuable with the original glass, even if it is clouded, i.e. in cleaning it you might break it..

Unfortunately, I was never able to get the story of how my dad got it or what it may have meant to him, so it is pretty much just a historical novelty for me at this point. Looking on eBay indicates there isn't much of a market for it either. So I figured that I may as well try to refurbish it as much as I can so that my future kids might be able to enjoy it.

I'd be glad to clean it up for you. Just send it my way. Now, I'll be honest and won't guarantee that you will ever get it back.

I don't know anything about these, but I can't imagine that cleaning it would decrease the value. Now replacing parts, maybe. Still though, I'd look at getting someone with experience in these things to at least put their hands on it and ensure it's in a condition that'll preserve it. Perhaps talk to the folks at the Museum of the American GI.

I imagine the US Army's National Armor and Calvary Museum would put it to good use.