Shame about your weather. I hoped you might get lucky.
I had a flight with my JayTee today, before my club's AGM.
Only one flight today as I broke a hatch catch, and the cloudbase was too low to loop (500 feet at a guess).
My Falcon 120 with a Wren 54 Mk3 came out under 15 lb dry. I built my own glass fibre 2.2 litre fuel tank, so I guess TOW around 18 lb. It flew very well, with no structural issues.
The only mods I made were a dab of extra glue around the fixing points on the booms, and a change to steel bolts.
I flew fairly gently and it held together just fine. Until I hit a fence post trying a touch and go..