I have put up side by side photos of the two 1972 Paramounts so that a visual comparison can be made. When viewed together the differences in fork rake and bend are fairly obvious, as is the more generous rear triangle area of the P-15.
I have hit my three post limit for the day, so I'm going to go take a nap. If there is any interest in it, I'll add a P-14 just for fun. Drop me a line if the link gets mangled beyond use, and I'll send it to you.
Lansing, Mi USA