I've made some progress on this build so I thought I'd update the thread.
As nice as the Vietnam dial is for this watch, its typographic style resembles the later 1960s text in the 7928, which is subtly different from the earlier Submariners. The only thing to do is print your own dial, so that's what I did. The text on this one is lifted straight from a front-on pic of a gen dial. It's interesting to note that there's some variation in the text and especially the exact position of the two text blocks in different examples of the 7922 and 7924.
After a while of looking at gens I realized that the text on the Tudor subs isn't negative relief gilt, it's printed-on gold ink. Similar to how some Rolex gilt dials have the depth or chronometer information printed on later, Tudor seems to have done this with all of the text, probably a cost saving measure. For my dial, I let the brass surface show through on the chapter ring and swiss text, and covered the middle area with a thin layer of gold paint. The result is pretty interesting; in some light the Tudor rose and calligraphic logo jumps out in bright gold, and at other angles the inner text disappears almost completely and the chapter ring shimmers instead. I'm really happy with that result. The lume on the other hand.. I need to get better.
I also replaced the hands with the closest things I could find to the 50s flat style hands. Still not perfect but much improved.
I've saved many pics of gen 50s Tudor subs and about 75% of them are found with a later service bezel insert with serifs and hash marks, so I went with the awesome, recent fat font insert produced by slay.
I'm pausing to enjoy it for a while now, but still in the works for this watch:
-Fleurier 390 movement
-dial gold electroplated rather than brass relief, with better lume work
-case engravings to make this a crossout 6538 case with the correct range serial number
-gen Tudor hands, although this one is more like wishful thinking
Any other ideas? Thanks for looking, and thanks to several people in particular who have really helped me with this project: @Bart Cordell @Alan72 @hologramet @JSebWC @slay