Seized bolts/studs

Please ignore if I'm teaching old dogs old tricks!!
Acquired a lovely old British vice that looked to be useful so went through the dismantling process for a general clean up and re lube.
Came to removing the vice jaws and of course the 60 year old fixings didn't want to play dismantle.
In these situations I use an oxy/propane torch on the head getting it nice and hot then I use a spray freezer, designed for electronic diagnostics, to rapidly cool the fixing - shrinking it in its now expanded hole.
Bit of work with an impact tool (hand held hammer type) and out they came with no damage to the heads.

Alan