The bakelite Brownie Hawkeye, meant to use 620, will usually feed off a 120 spool but needs a 620 take up spool. Quite good pictures from these. With the lens reversed, it makes some really wierd effects.
I use cut down 120 film in my Brownie Six-20 F - I trim the edges of the spool and it works just fine, though the take up spool is usually where things get complicated, so I use a 620 spool for that if I can. It's really surprising the sort of results you can get.