"Hello, we are making runs of the 642's without the lock."

lol. gotta love those non-answer answers. as to your gun being worth a whole bunch of money, i would say it's worth at least $350 these days. collector's item? probably not so much.

taking off the sideplate is easy. there are videos on youtube to show you how to do it (tapping method). whatever you do, just don't pry it off