I've just snapped 2 bolts, why ?

Update, rebuilt my new head & fitted.
Fired up the bike & hey ho, no oil leaking now.
I'm pretty happy now. (Until the next problem !)

Can you get some saddle time in before too cold or too wet season starts?

That head can be repaired and very little cost, also be careful if torquing chrome plated bolts, they have a much lower torque spec as the surface of them is far more slippery.