Cofebiz----hope you learned alot from this. However, When my cohorts speak of UL-----------I did not see a town of reference for your sign, and it might not, by virtue of the AHJ, meaning the local sign inspectors, i.e. the local town electrical inspector, might NOT require a UL sticker. So, that alone can't be an absolute.
Putting the neon in afterwards------------like my cohorts said--------not the best, definitely not the easiest way. Your letters, being mounted on a raceway, the transformer WILL be inside the raceway. What you won't know---------and based on this guy's fly by night attitude--------whether the tranny is the correct size.
Looking at the pic, and you stating twice that the letters will be double stroke-------------sure looks like a tight fit for two rows of neon.
If you have access to, and are comfortable climbing a ladder. Set the ladder up, pull the plex off a letter and look, inside. You'll see if the holes, the housing, wires etc are in the letter and raceway. If you have access to the top of the raceway, lift the cover off, see if there is a tranny. If there is a tranny, look for a factory label on the tranny. Look at the tranny and see if its new-----------oir looks old. Either way, look at the plate, see if you see a 15,000 volt secondary voltage, a 12,000 volt secondary voltage, etc. Might be a 9,000, 75,000----------take note of what it is.
When the guy, IF the guy, finishes the sign----------do NOT pay the balance until the sign is lit, till you have the time to ope the sign up, and see if the neon is truly two rows of neon, or only one, etc, etc. Not that you'll really know what you're looking at-------------but you'll know what you DON'T have in the sign!!!!
With the guy working at HOME depot------------hold that over his head to finish the job. I doubt seriously that Home depot would like one of their managers screwing the public like that-------------might ery well lose his job over it.
Hey, keep us posted on what's happening on the sign. Make better business decisions in the future---------or you might very well be back at your old job!!!!
Now------------------where's our coffee????
gn