The Dynaco SCA35 fits the integrated category, has the same output Iron as the ST35 and can be modified( probably require some re-fit for reliable day-to-day use anyway ).

The Heath W2 is a 6L6 amp, but has a 10k a-a output TX, and a seperate power supply, so a bit of work would be needed to fit El84. Mostly PS building, and socket swapping. It probably has better output Iron, but I am just speculating there...

And then there are the Eico and Scott to consider...
cheers,
Douglas