I have a MG Ward 18/42 Briggs twin, Having oil seeping from what appears to be the left cylinder base. Is the Jug removable or cast into the main block. Cylinder head looks easy enough to remove but the problem appears low end. Thanks rirog

No, Like on mine it may have a rear section that's removable (plate), but that's it... engine must come out and the crankcase base (sump) removed and the gasket replaced... (its probably from the base gasket)

Clean it up and keep a check to see exactly where (be sure to check the oil and make sure its full every time you use it)