Derek
Could you not do it yourself?
1. Drain oil from engine
2. Unbolt engine from mounting and move it back to allow access
3. Unbolt crankcase cover, undoing bolts in opposite sequence.
4. Remove old gasket and fit new one
5. Whilst there fit a new crankcase bearing (housed in the crankcase cover) for the crankshaft
6. Put crankcase cover back on and do up bolts in opposite sequence to retain flatness when tightening (supposed to be at a certain Nm but generally quite tight to very tight is perfect.
7. Move engine back in to place and bolt to floor again.
8. Put oil in (hey, may aswell change filter too).
9. Be safe in the knowledge that you have saved a whole day, and a load of wonga
Mark
p.s. failing that why not ask Dave Ingram?