The only issue with going the Vietnamese route is that the dials are undersized for the Raffles case. Raffles takes a 28.5mm dial, whereas the Vietnamese ones are stock size (26.5 mm IIRC).Vietnamese sellers like Ruby, MQ and Phong have true negative relief gilt dials that are pretty good. Users here on RWI have also made them with both decal paper and with a process a little closer to what you described but more suitable for a DIY'er, as linked by DeLoMan above.
I should have my dial blanks in this week to give the technique I try that I linked to. Trying not to get my hopes up, but I think it could turn out great based on the results of others. Fingers crossed!