Saving Old Seagulls

I must have watched a 1000 videos on this
from what i can tell, the standard process is to drop the muffler pipe to get to the water pipe olive
there are signs of a seal/o-ring at the top as you can see, but the pipe is not budging from the top
i have tried taking a propane torch to the top section to expand it, but worried i'm going to wrap and buckle the pipe

Remove the drive shaft tube from the crankcase first, then you'll have the bottom end of the exhaust tube loose, now wiggle it about!

had to upgrade my butane torch and heat the thing plenty but got it off

does anyone know the original paint type for these. posts talk about hammerite, but that cant be the original