Extra Sign for Trolley Barn

Looking for a place to purchase an extra sign for the Operating Trolley Barn (6-22199).

Lionel website says it's not available. Here's the SK: 6202199029

Barn comes with only one sign but I see a place to mount it on either end so would like to have signs on both ends.

I did a search on Henning's Train; didn't find it there.

Also tried a search on The Train Doctor, but also didn't find anything there - although I don't understand the numbering system they use so may it's there?

Thanks.