Rare Ladies Datejust, Advice and Info Please... Take 2

[michaeljpeck]

does anybody recognise this particular model?
ref- 69138. ladies 18k yellow gold president bracelet, original diamond bezel, year 1991, rare and unusual champagne dial set with 64 embedded diamonds.
the dial is what i'm stumped on, beside the diamonds as you can see it has the gold number spacers and roman numerals around the edge. at first I assumed it was an after-market dial, but after being taken apart and inspected, I was told it was completely original. which leads me to believe it must be a one-off production, as I can't find anything remotely similar to it..
would greatly appreciate it if anyone could shed some light on it?