Rolesor is the term Rolex uses for their two-tone models. At 14 karats, it would be difficult to recreate the weight and tone of 18k gold, and I don't have the means to test out a bunch of different alloys (once I make an alloy, if it isn't right, it takes work to reclaim the constituent metals). Rolex likes to tout its proprietary alloys, but historically, they really aren't all that different from industry standard mixes.
What I can tell is if you put a gen rolex link side by side with let’s say, a startime 18k link the color is noticeably different being a much lighter tone than the startime one, which is a lot yellowish.
How that 25% which is not pure gold is composed makes one hell of a difference in how the gold tone looks.. About the weight I’m totally with you, it would be a pain in the ass to match it.
But imho the greatest pro about making a gold case is having a watch which color can’t fade. I’d say this is much more important than having the weight a bit off, and would still be a big improvement over a stainless case.
If I can give you an advice 3D gold printing is a thing, I just had some mid links of a bracelet made out of it.
This helps a lot on recreating the threads correctly on a case!