Good ideas all.
The brain trust out there is always amazing.

My vote is with MOVING the tail mounted servos to the centre and going pull-pull, or whatever works.
I did this on a Yak and it works just beautifully. EXCELLENT result, even though I had to manufacture my own servo trays, supports, etc...

The corollary: I also totalled a very nice GP 50 size Extra by having tail servos, and a bunch of weight to compensate.
Flew like a brick. Hey, my thumbs, my lazy, etc., so no excuses at all, but it was a brick. I destroyed a perfectly useable airplane by NOT doing the right thing, and moving items forward.
I keep a chunk of THAT mess on the shop wall just to remind me not to get lazy!

IMHO, adding weight is ALWAYS an absolute very last resort, as it is total loss of performance.

MOVE everything to the wing tube area or even farther forward. Make up servo trays, epoxy them in, do the pull-pull if it is possible, etc...

Good Luck!