That looks very nice indeed.  You have earned that "longish lay down".

My experience with brass boiler bands is far more positive than I had expected at the outset.  One thought would be to use a lower melt solder paste if you go the brass route.  That brass boiler does look as though it would need a lot of heat to sweat the brass bands onto it.  Which may be why Slaters provide plastic bands as an alternative?