"Definitely Original" 346 number plate on Ebay

Last night asked me about a brass #346 number plate on Ebay. He wanted to know if I thought it was original. It is 6 inches in diameter and is clearly undersized--not to mention, 346 has its number plate now. I emailed the seller and told him it was a repro and he responded saying thank you. However, I noticed he has not edited his listing and still claims it is original. Nor did he post my message to him, though he posted others he received that do not say it is a reproduction. Didn't the Colorado Railroad Museum sell these things in the past, like in the 1960's? I just would hate to see someone spend a lot of money on this number plate thinking it is original. I would not be surprised if others have contacted him as well telling him it is a reproduction--or maybe they should do so. Anyway, here is the link to the auction:
[cgi.ebay.com]