I think that's pretty much it. As far as anybody knows the slotted screw was present throughout filming and the Weaver knob was only seen when the gun turned up at World-Con 2006. It's probable the slotted screw was used to hold the cylinder crane in tightly from the opposite side and this may simply not have been replaced when the gun was unloaded and placed in storage for the last time.
Personally I prefer the Weaver knob. From a practical 'in universe' point of view a slotted screw isn't very practical on a Police firearm as whatever it adjusts requires the use of a screwdriver but a knurled knob with divisions engraved on it which can be turned with the fingers to adjust some parameter on the gun is much more practical for a cop on duty (and possibly under fire).
im brand new to prop making so i am not yet attempting exact replica but here are some pics of my project currently in work , everything is 3d printed in resin on my mono x resin printer, printed grips in clear resin then sprayed them with come gloss super clear to make em shiny. bought the electronics and leds from someone here on rpf, working on that right now , i have zero experience with solder or leds though so not looking forward to that part. metal finish achieved with paint and dry graphite powder