The Bassman LTD
By speaking of a Bassman, usually the '59 Bassman (and its editions) is meant. The hype about the vintage models is as always just a matter of the collector. From 1982 to 1989, this model was reissued as "Bassman RI" by Fender. If you call a RI your own, it is best to rebuild it with the old circuit of a 5F6A. But please on a fiber board and with metal oxide resistors and silicone cables.
The best Bassman is the current "Bassman '59 LTD" with the green Jensen speakers. The cabinet is massive again with lacquered tweed. The circuit has the more "modern" tone stack and better presence control. The rectifier tube is back.
My Bassman was in pretreatment at Finkenhäuser. He matched the tone stack pretty well for harp, but generally attenuated too strong. And this stupid G2 regulation was broken.
Now AY-AY-AT preamp tubes are installed. You might want to replace the AT by an AU. The tone stack is modified at R17 (470k put over it) 82k, C5 replaced by 150p, C7 (22n put over it) 44n, as usual. The Brightcap (C4) is omitted.
The picture shows the two removed condensers and some components that have been added. If possible I would not disassemble the board, because the mechanical stress often leads to cable damage.
Based on my other amplifiers the Bassman got a jack for looping external FX devices. If you need just a little reverb, it comes in quite handy to put the "stuff" in the back of the cabinet. In the picture at the anode of the normal channel (above R8) you can see the 6,8n which takes some heights. Bright and Normal can stay.
In the NFB loop you can find a 470k / 4,7n parallel circuit now. This mod was already done in this Amp. I changed the cap a bit by ear.
In the picture you see the 9V power supply with appropriate jack.