RCA 630TS which one came first? some minor variations

[doug621ts]

Im not sure if most of you collectors ever really noticed some of the minor differences between different RCA 630 sets electriclly and outside physically. I have had both RCA 630's, one with the single clip to hold the glass in front of the screen and the other that had four corner clips...which one is the earlier one? I have had 630's with the channel escutcheon made of plastic and others made of metal with slight different positioning of the channel "one" number. Electrically I have seen these sets with "electro-magnetic ion traps" and others with the typical "magnet style" and the wiring of the sets, some with rubber coated wires and some with cloth covering. This not just limited to the 630's but I have sen this with the 8TS30 and other early RCA models. Any thoughts or reasons on this? I would like to hear some "expert" thought and feedback about this!