I stumbled across a reference on the web a few years ago regarding peelable, laminated, head gasket material used on British bikes. You would do a dry test assembly by setting the head on the cylinder sans gasket, and measuring the gap between surfaces. Then peel a gasket that was .002" thicker than the gap for "squish".
Personally, with the Bullet and it's low compression, as long as the gasket used was at
least .002" thicker than the gap, you'd probably be just fine. Unless you have access to a machine shop that can accurately measure the spigot height to the groove in the head I wouldn't get to fussy as long as there is enough clearance to get her down level.
FWIW, when I did my last head gasket I used a stock gasket and some aircraft sealant called TiteSeal, medium weight (available from Aircraft Spruce & Specialties Co.,
www.aircraftspruce.com ). A thin coat on both sides of the gasket. I torqued the head to 165 inch lbs (Yup, that's much less than the book values!) in three lifts of 55 in lbs each with a little time in between each lift. Hasn't leaked a drop of oil from the head gasket which had given me fits for a long time. That was about 1,500 miles ago.
The only leak I now have is from the primary and Vince tells me it's because of the new, factory suggested 880-1,000 cc of oil in the primary compared to the 440cc of the manual. (Have a Leak/Save a Starter.)
I posted pics in the thread I wrote about the head . I don't know if I got around to the gasket installation or not. Look in Tech Tips:
http://www.enfieldmotorcycles.com/forum/index.php/topic,2277.0.html-Jesse