Hmmm, sorry I missed that. Don't know what I was thinking. Anyway, the Swap/Update block command should have redefined the block in your drawing, and any subsequent insertions should be using the new block definition in that drawing.
If it works correctly on the drawing you did the Swap on, but not on other drawings it may be a library path issue.
Can you post the files that I could take a look at? Perhaps the original drawing and the new wire number block? I'd like to take a closer look.