Tom, et al:
I have four 1st Gen record fronts. Two are slotted, two are not. Three are the standard old, ho-hum 1st Gen....but the forth, well I got good news for ya buddy! The forth one has the flat slot head retaining screws as you describe. Well, at least the two body-pivot-studs have these screws. Upon examination, the top-cage-to-top-pivot arm is definitely a blacksmith job. I got it off eBay, and just figured it was a home machinist job. One is an oddity, two are a pattern. Send me the jpegs, I'll get my digital out tomorrow and send you a pic of mine.
Costa Mesa, CA