Barrel to Block interface

[tobyd]

Any good ideas on removing the barrels from the block?

Cylinder head removed no problems but the barrel is pretty firmly stuck the block - It will hold the weight of the engine (for a few seconds until I put it down again)

tried hitting it with a rubber mallet at 90 degrees on the reinforced bits of fin and the front casting points and back cam tensioner house but hasn't really helped?

update: A friend and I can lift and shake the whole engine by the barrel, its stuck that tight... I can't see there is anything else holding it in place, just the 8 studs which look like they have plenty of clearance should they have corroded, 2 locators buried at the back (from the diagram) and the pistons which are free. There is a little play at the back by levering a length of wood over the starter casing but nothing at the front. I can't believe the gasket is strong enough to hold the two parts together!