I love the jubilee for sure.
In my opinion is a straight forward rock machine just like any other classic Marshall circuit but with it's own voice.
If you try to make it sound like a different Marshall you're taking the wrong route.
Sell it and buy the marshall that makes the tone you're looking for. That's true for any amp, or guitar, actually.
Had the 100W with a 4x12 with V30s now I play the 20W with a 2x12 with greenbacks.
Contrary to the common opinion I think greenbacks work much better with this amp. But of course is a matter of taste
I used to run the gain between 6 and 7 but I've learned to appreciate this amp even more with gain at 4 with gibson paf humbuckers.
I run mine with with Bass @ 10*, mid @ 6, high @ 4, presence to taste, usually under 5.
Lead volume @8. Rhythm clip gain off.
*With the 100W or a 4x12 bass @ might be too much.
I use the clean channel occasionally but I most of the time simply turn down the guitar volume.
Played a gig yesterday, open air, had the master at 5 but 3 songs into the show I've been asked to turn down to 4 by the sound guy.
The amp sounded simply awesome.