If he's gotten two differant measurements in 2 tries and they are .125" differant ... My guess would be he has NO idea how to measure Comp. Height.
Personally .. I would give the guy his money back, he's not worth the hassle and you'll probably never be able to prove to him that the CH is in fact 1.270".
If you want to give him another try ... ask him what CH he is looking for .. exactly ... and have him take them to a shop and make the measurement ( and give you contact info to that shop ) and if they measure at 1.270 then he pays all the extra shipping / measuring cost.
Myself ... I'd count my losses and move on