Look on facebook for Charles Smith Neon Clock Parts
He's got a website too, but I dont think a lot of the parts he shows as having are actually in stock. I know the NPI clock framing he has was out of, but it shows on his website.
http://www.neonclockparts.com/My brother just did some acid etching on brass, came out amazing to make a brass tag. I'm wondering if you do Paul's suggestion and get some aluminum stock and mask off the lines, you could chemically etch it and make a pretty good repro piece. I'm not sure how well aluminum etches but I see there are some youtube videos on it.
If you need to buy aluminum angle I would check your local Metal Supermarket or other metal distributor, HD and Lowes are just crazy expensive for metals.