Kolster Audio Output

[RDusel]

Fellow VK-ers,
I'm restoring a 1931 Kolster K60 radio and I'm almost finished. Case came out nice with the original finished cleaned and recoated, all caps and resistors changed (first time I have seen a radio with all dogbone resistors off value), tubes tested and set re-aligned.
The problem I have is that the radio has a slight bit of distortion that did not go away with the re-alignment. Selectivity, Sensitivity are both good but the radio when tuned to the best always sounds like it is just off station a hair.
All coils check with the correct readings but the speaker sounds a bit off, weak on bass (it's an 8" field coil unit, 3ohms) yet the bass returns if you slightly touch the back of the cone.
So I found an NOS Jensen 8" speaker that has the same coil ohms (3) and the same field coil ohms and fits the mounts perfectly.
My question has to do with the output transformer. The factory transformer is rated for a 650ohm primary and a .3 ohm secondary SE.
After reading up on audio output transformers I find that the #47 output tube in this set "likes" a 7K ohm impedance primary. So I bought an output transformer designed with a 7K primary impedance and a 4 ohm secondary impedance.
My question is which transformer to use? Stick with the stock unit that the set was designed for or use the newer unit that matches the specs I found for a #47 tube. I'm thinking the newer transformer may offer better sound from the closer impedance match.
Any and all opinions and advice would be great. If you have any questions let me know.
Circuit diagram attached for your convenience. Thank you all for your help!
Rob