Compare MM o/p xfmr models

[dugdiamond]

Can anyone explain the differences of the various Fender Twin output transformer made by Mercury Magnetics and maybe suggest a replacement for a 1974 Fender Twin Reverb Master Volume push pull gain model, 100 watter, that has had all circuitry changed out to AB763 circuitry and a B+ voltage of 450 volts ?

Mercury advertises three 100 watt versions in their ToneClone and Tone Clone + models...
FBFTO-100
FBFTO-100M
FBFTO- 100X
all three version offer the same multi-tap output for 4-8-16 ohms.

Mercury offers similar 85 watt versions of the ToneClone and Tone Clone+ series ...

FBFTO-85 single four ohm
FBFTO-85FS single four ohm
FBFTO-85M w/4+8 ohm taps
FBFTO-85MT w/4+8+16 ohm
It seems as if "MT" might be for multi tap 4/8/16 output?

"M" is for the dual 4/8?

Both the plain "85" and 85FS are single 4 ohm output transformers, so what is different besides prices?

Patrick at Mercury is on holiday and can't get any answers from others.

Might anyone lend a clue as to what to base the choices besides price?

I assume that using a CBS based post AA270 Silver Faced circuit based amp with it's original stock power transformer regardless of circuit topology will have a higher voltage and that the FBFTO-100 series would be preferred as my 450v b+ might be a bit higher than typical Blackface AB763 circuitry?

Besides prices and number of output taps what are the differences?

I understand that there are many opinions on different brands of iron and not all agree on the premium retail prices. But let's keep the debates out of it and stick to the differences in what all are listed as Blackface ab763 twin o/p trannies. Does anyone have a clue as to the model numbers and differences?
I think this is going to be a tough one....
Thanks Man!

[Helmholtz]

Fender used the 125A29A in their "100W" TRs at least until the early 70s. So that would correspond to MM #FBFTO-85. Both only 4 Ohm.
The 100W MM models seems to have different mechanical dimensions.
Problem with MM is that they don't publish comprehensive specs like e.g. Hammond.

A B+ difference up to +/-20% shouldn't matter for a top quality OT.