Megatech's website is:

www.megatech.com

But there isn't much info there.
As to the leak, there shouldn't be a gasket at the head. You are more likely to find a metal shim between the head and the crankcase. The shim is to control compression, if it's even installed. The glow plug does have a metal seal and if this is missing, it could lead to leaks. How does compression feel?

Jesse