The top one looks like a 1930's NEW with a fat standard bar handle - there has been some confusion over this model as to whether it is a NEW or a variant - could you supply a photo with the cap off?
The lower one is most definately a 1930's Gold Tech.
I don't much like the Tech as a razor - the Gold Tech is one of my least favourite razors, mainly because to me it marks the point where Gillette for the first time releases a razor design that is actually not as good as the one it is replacing (the NEW).
The Tech bar guard was easier and cheaper to produce - stamped out from a sheet of metal - but it also feels & looks so much cheaper too. The handle may look heavy, but it isn't it is very light ..., later thin handled Tech's are heavier and better balanced IMO. The shave from a Techs is very mild, a little too mild for my liking.
The NEW is a great razor - not as mild a shave as the Tech, comparable to a HD in aggressiveness I would say - more to my personal liking.
That particular model has a handle that looks heavy but again is actually much lighter in weight than it looks. Personally, it is about my least favoured NEW model - the Deluxe models in the Belmont style etc are really something special IMV, but they were a much more expensive range originally..., god I'm picky & coming across as negative.
That razor of yours is still very nice, especially when compared to more modern instruments - a great shaver.