BikerBob,
The Bilgram diagram is a very handy tool to lay out the port face and valve face. I can walk you through the design of this engine. The thing I need to know is the length of the connecting rod and the design cutoff as a percent of the stroke.
If you are using Jason's suggestion of 3/32" holes then we know the port opening to get the ball rolling. Most of the model designs I have looked at have 0 lead so we can ignore that. The full size Shays I study have a 1/16" lead and when that is scaled down to the scale I work in it is very tiny so I use 0 for the lead.
If you want inside lap for compression and release then we will need the design point for that which is usually 0.9 x stroke.
The steps for doing this are in the article, but to be honest, I did not understand it the first 20 or so times I read it the first time I came across it.
Cheers Dan