seized core slugs

[Yorkie]

If shellac is indeed the sealant, then meths is the correct solvent. The 'cement' often used for securing valve bases to the bottles and also to fix top caps on valves consisted of wood flour and shellac. Loose valve bases can be g'lued' back by dribbling shellac sanding sealer round the joint, but if the joint is too slack and the sealer just dribbles through into the base, it can be thickened up by adding some wood flour. It will stick better than other adhesives because the shellac will bond to the original in a way that such things as Araldite or superglue won't. Just use a piece of scrap wood and rub it with 80 grit sandpaper until you have enough 'flour' to mix with the shellac. (Irrelevant to stuck cores of course, but relevant to shellac and meths as a solvent).