Looking at the moments - weight times distance of your components from the wing LE (rough numbers), we balance about the same but I'm 6-7 oz lighter:

Yours: [(19.5 oz (550 gram engine) + 14 oz (deadweight)) x 10"] +6*0 + 2*0 = 335 in-oz, 41.5 oz (your battery and servo have zero moment arm at the LE)

Mine: [22.9 oz (engine) x10 "] + [(10 oz (battery) + 2 oz (servo)) X 8"] = 326 in-oz, 34.9 oz

Moving the tank wasn't hard. Yes you need to cut part of the dash board and cockpit floor.

Good luck. Hope your hand gets better quick. Lousy when they bite.