Hey c70man,
I think you would find that an 80s D-35 would hold its own, volume/projection-wise with your D-25 and D-50. I had both '72 and '78 D-35s, along with '74 D-25 and '92 D-55 (plus a '74 G-37), at one time. The '78 D-35 certainly could match the 25 and 55 for volume. The '72 D-35 was/is a bit quieter (tho' still plenty loud). Both D-35s have/had a more balanced but "brighter" sound than either the D-25 or D-55, tho... the arched back of the D-25 and rosewood of the D-55 emphasize the bass end more than the flat mahogany backs of the D-35s. The voices of my two D-35s also were different... the '72, tho' not as loud, seemed more balanced, had better bass, and seemed a bit more mellow to me, while the '78 tended to emphasize the mids, and was a bit more "brash" and "in-your-face." The '78 was also built substantially heavier than the '72. I preferreed the tone of the '72 (plus, I had bought it new when I was 17), so kept it and sold the '78 when I got my D-46.
Dave