Hotshot resisters and other questions

[DaveB 151]

Hi

I've recently acquired an almost new vintage Hotshot which is in incredible condition. There are some few minor issues I need to address, one of them being that the resistor wires were soldered on to the resistor pins but two have come away and need reattaching. What I need to know is, can you still get hold of the original Tamiya heat shrink tube and, if not, what would be a good equivalent? 

Also, theres some ancient Futaba radio gear fitted that I'd like to swap out for some Acoms, can you tell me if I ditch the kit supplied BEC switch if my acoms receiver has BEC built in, would I just use the acoms supplied standard switch? 

Any help much appreciated, thanks