I have had a 94 sporty (1200 C0nversion) for about 2 years - in the last 2 weeks , the primary is leaking from the lower front case to crankcase bolts. Is this just caused by a gasket failure or is it possible I have blown the engine main seal

Just sounds like a leaky gasket... time for a new one..

Degrease it and then ride it to see exactly where it's comin from