Hi rmjmusic,
The getMidiModule function accepts string or number as optional arguments. Most likely you are missing quotation marks.
(Unless lfo1 is a variable which has a string or a number assigned to it)
this.parent:getMidiModule("lfo1"):setParameter("RateSync", ratesyncTypes[RatesyncType].index)
Assuming you have four mono lfos named lfo1, lfo2 … it should work.
I think the index numbers for the actual values of the rateSync parameter should start at 0 so you get the range of 0 to 22.
You can quickly check this like this:
rateDef = this.parent:getMidiModule("lfo1"):getParameterDefinition("RateSync")
print(rateDef.min, rateDef.max)
Apart from that the script should work fine.