Say, how were the old original Fender Bassman heads? Would it be worth trying one of those?
You're asking kind of a loaded question. There are many flavors of old Bassmans; the design changed tremendously in its history. The original 4x10 Bassman combo is one of the most coveted guitar amps of all time, but it's not much for bass unless you like Lemmy tone at low volume. The later "Blackface" era amps were revoiced with less midrange and came as separate amp/cabinet combinations, but still lacked any meaningful power.
It wasn't until the 70's, under CBS's ownership, that the Bassman 100 and 130, Studio Bass, 400PS and 300PS that Fender actually made a "bass" amp (Showman doesn't count; it was a multi-purpose amp) that bass players could use. Before the vintage craze went retarded for ANYTHING pre-70's, you could pick up Blackface Bassman heads all day long for $200-250 just because they aren't really good for anything outside of studio, and even then, there are MUCH better tonal options. Unfortunately, they also applied the same design philosphy to their guitar amps and guitarists bought the lions share of gear and guitarists who had discovered distortion weren't interested in more clean power. Your Music Man HD130 was borne out of the same philosophy, but is a better design than its contemporary Fender counterpart, the Bassman 130.
