I was looking at these two guns at my LGS. The Model 29-3 Serial is N925260 and the 28-2 is N519677.
Both are in good condition. The Model 29 is in the best condition with just a faint drag line and nice grips (I think target grips).
The Model 28 has more wear but still looks good. It has the side panels as grips.
Can someone look up these in "the book" so I can get a idea of the age?