When you installed weight, do you mean that accounts for everything like the pump etc? At 2.2 lbs that is lighter than a modern K100g at 2.9 lbs for just the motor. The K140g I will be using will be at 3.7 lbs.
Should help get some weight back there for balance. When I assemble this I will ensure I put things back further.
Sounds like the fiberglass is ok from my previous thread. It had me worried but it seems strong.