Righty then, a further update.
I've finished the basic shape of both sponsons, ensuring both are a snug fit without having to make any alterations to the fuselage, I've left the bottom of them until after they are fitted and the fuselage closed up.
And this is how they look in place on the airframe, the starboard sponson needs a few more recesses cutting into it, as well as the half-moon plates fitted at the front ends to presumably mount the HIDAS equipment, also lots of scribing and mesh detail to be added
finally here was a fun little project - this is the kit M261 rocket pod with the rounded fairing at the front,
I sandwiched layers of plastic card together, then carefully drilled (not very carefully on the first attempt!!) the 19 holes , after this it was cemented in place to the kit pod and then dremelled down to the rounded shape.
It took two attempts, but here is the finished pod which I'm quite pleased with