We just installed a 6'x6' internally lit sign, push thru letters for another sign shop... about 4 weeks ago. It was about 12" deep. The sign was all wrapped up, but I tried to look to see where the screws were along the top or bottom.... or down the sides. Never saw any on the face. (hmmm) We had to put this on a brick pedestal, so we had to strap it to the boom and lower it onto the tubes sticking up. Wiring came up through the bottom, but no place for it, so we made a hole. Thing is, the sign sat flush, so we couldn't put a conduit fitting on it. Anyway, as I mentioned, some idiot used the same method as your customer. They welded the frickin' front and rear panels onto the frame, so we hadda run our straps from side to side. However, this made for a very difficult mission of connecting things in the middle of the sign. Now, we got everything on and left the site, but I told the company who hired us..... don't ever call us to service this sign, cause without burning the faces off, you can't get to anything. They had light bars running every which way inside and wires all over the place. Talk about a mess. Good luck with your customer.