[drc]

I don't think it's for the original cards. The length of it isn't a big deal to me, as it could have been cut down or the entire 'printing plate' could have been made of movable pieces. Newspaper printing plates were often made from multiple parts.

It is in the form of some old time printing plates, some which had the metal front on a wooden back.

I'm not saying I think it's a forgery, nor am I saying it's not vintage. Perhaps it was used to print a period ad or sign for the cards. That would be a valuable item too. It seems highly implausible that someone would forge this, considering the time, effort, expertise and cost required.

Just my opinion.