21 T spline

we have a 1970's WABCO (Westinghouse Air Brake Co) earthmover and the spline collar on the output shaft of the front motor is hammered.  We have found a waterjet guy who says he's cut splines for other construction and mining equipment, but he nor I have a spline wizard on our CADD programs.

The collar is pretty trashed, and the male spline is in a very hard to get to place, so it is hard to get good measurements.  So we are thinking of making a ring to some ANSI standard spline (B92.1-1970?) and seeing if we can get it to fit. I have a 3D printer and if that works, then we'd cut a thin section on the waterjet to confirm.  However, i don't see a 21 tooth spline in the 17 "common" pitches in my 19th edition Machinery's Handbook.

Might someone have a plugin or knowledge or gearotic etc to help make a dxf of said spline, so I can give it a try?  Sorry for the spartan dimensions...

1970's made in USA machine 

spline teeth - 21

pressure angle 30 (guess)

major dia is ~2.75 (across an odd number of teeth)

minor dia of male shaft ~2.56

I can try to get other measurements that might be helpful, but it is tough.

thanks in advance for advice, help etc.

Chuck