Need advice - Resizing a sallet pattern

[Cat]

Ok, I have been commissioned to make a leather sallet, and I think I am going to use the helmet bowl from this pattern:

http://www.armourarchive.org/patterns/sallet_rainald/

How do I resize this to fit the customer's measurements? I was thinking of getting the front to back caliper measurement, the side to side caliper measurement, and some sort of top of head to jaw line measurement. (Is the jaw line the proper ending spot?) Will these measurements be enough, or do I need to get something else? I don't know if he will be using padding, but I can accomodate that I think by adding on to his actual measurements.

Now, what do I do if the proportions of the pattern don't match up with his actual measurements? Do I try to freehand the pattern shape, or is there an easier way?

Any tips or advice would be greatly appreciated! (And just for reference, I won't be using the tail and faceplate portions of this pattern, at least not without some modifications.)

Thanks!
Cat

[Cat]

BUMP