I think I might have found the elusive Williams gear ratios but they might also be wrong.
The whole page is here : http://members.tripod.com/~clubcliowilliams/el_auto.htmhttp://members.tripod.com/~clubcliowilliams/el_auto.htm
the ratios supplied are
1st - 3.09:1
2nd - 1.86:1
3rd - 1.32:1
4th - 1.02:1
5th - 0.79:1
Final - 4.06:1
Seems to very similar to the 172 ratios except for first where the 172 is rated at 3.36:1
can anyone comment on whether these sound right?