Phil, that is a nice looking jig! Looks to be walnut?
What Semo says is true. There is really no universal jig when it comes to measurements.
The principles of construction are the same, but we tend to twist and measure loops for different bows such as longbow and recurves differently!
When you make your strings keep notes, mark your jig as such. You will have to "Custom Fit" the jig to your style!
Just like Glass bowyers, the construction principles are the same, but the formulas to acheive them are different!
That's what I say, cause I mean it! :D