removing float pivot pins when there is not enough sticking up to get a purchase on, does this mean destroying the floats?

FWIW I tend to hold the carb body on its with a loose clamp i.e. holding but not crushing and then tap the non-machined end of the pin with a pointy thing (I use an old dart body). This gives enough to get a grip.
Best of luck Steve

Mine goes into a blind hole by the jet that sits into the bottom of the float chamber the on wth the o ring on it.

Oo-er that’s a new one on me.

Hole side down and tap the blind side a few times with something solid. I’ve never come across one that’s tight. I’ve even pulled them out with a magnet.