I had a Senior Telemaster.

My mods:

Bombay
bolt on wing
.60 two stroke, then .91 four stroke
balsa USA 46" edo floats
Aluminum struts.
Tail bracing wired

I even had a Zenoah G23 on it briefly, and a Maloney 100. The G23 shook it too much. (hey, I had to try!)

If I had to do it again:

1. Flaps, to get really really heavy loads off the ground. (but it probably isn't necessary)

2. Aileron differential, and couple it with rudder (especially flying with floats) makes the turning much easier.

3. I would definitely sheet the fuselage, to get ring of the twist/flex possible.

4. Servos behind the payload compartment.

5. Less dihedral in the wing.

This is probably one of the all time best rc aircraft ever produced, the 72" version included. One day, I set the throttle back on the .91 four stroke, and trimmed it for level flight, and did circuits for 10 minutes just with the rudder.

great plane

Billrad