Miller / Cragar Date Code? Help

[Stoker32]

We're building a 28 Roadster with an original Miller / Cragar OHV conversion. It's a B Block, and when we got it it had the original Cragar Valve cover on it.

Is there any way to tell what year it was made? I see there's some casting #'s on the outside and some markings under the cover. There's also a 1947 stamped under the cover. Is that the manufacturer date or a re-build date?

Any help is appreciated. Here's a pic.

Thanks in advance