Mixed up Merkur caps... help?

[Porky Pine]

I left my Merkur long handle (about a year and a half old) and my Merkur open comb 1904 (about 4 months old) disassembled where I dry my razors, then lost track of which cap went with which. The dimensions look very slightly different, and one has a '1' on the bottom, and one has a '4'. Can anyone who has either of these types kindly tell me what number they have on the bottom of the cap?

[RKG]

My 1904 open comb has a '4' on the underside of the cap.

[alex2363]

spotz, dowm boy....

[talibeard]

The plating is different; the 1904 is nickel-plated (yellowish) and the long handled (23C) is chrome-plated (blue-ish). You should be able to see the difference in day light easily. Good luck!

[Porky Pine]

Hmmm... the plating looks the same on top, but the number 4 has more texture and is less shiny on the bottom. Also dirtier which might suggest it's the older one, but based on where it was lying, I originally thought it was the 1904, which agrees with what RKG said.