I know who makes your gears and should be able to get replacements for you.
Also your calcs above have only been partially finished you now have to multiply through the "compound" gear set...
4th is direct and would work without the laygear being fitted, however the teeth on the input gear (19) drives your laygear (25)
As the formula is driven / driver = 25/19 = 1.316 (we will use this later)
1st ratio between lay and 1st gear = 29/15 = 1.933
2nd ............................................... = 25/19 = 1.316
3rd................................................. = 22/23 = 0.957
Now the answer we got first comes in to play...
Driven1/driver1*driven2/driver2
1st = 1.316*1.933 = 2.54:1
2nd = 1.316*1.316 = 1.73:1
3rd = 1.316*0.957 = 1.26:1
4th = 1*1 = 1:1
You're a gem! I will pm you about replacements. Is that a decent ratio or is it pretty bad?
Ryan