Difficult to answer, but logically serious collectors wanting an original watch wouldn’t buy it - full stop. Think of a DRSD or a Red Sub that has had those dials replaced by a standard white service dial, the cash reduction would need to be in five figures. In the case of a DRSD it could be £20k to £25k.
There may be someone who would buy it if the price was competitive, but are there bargain basement buyers at this level. I would very much doubt it.
I suppose the correct answer is that changing the dial sort of destroys the value of the watch.