That is a very cool mod. Acrylic gets a bad rap but it's far more durable than most people think and is easily polished if it does get scratched.

My favorite watch I own is a Longines Conquest Heritage Limited Edition 1954-2014 with an acrylic crystal. For a watch that is basically a 1:1 reproduction of a 1954 watch it was an appropriate decision by Longines. As was staying true to the 35mm case size.

 

Thanks. I agree acrylic crystals are way under rated. I also think they look so much nicer, especially the way the hesalite crystals bend the light at the edges near the bezel. Longines understood the reissue craze, and your 1:1 reissue is an example. Omega never was going for a reissue with FOIS; its not even close to 1:1 for sure. I wish it had been a real reissue, but then maybe it would be double the price or more. Im happy with where I am with the dial and crystal swap. And when all finished, the watch was still under $5k, which is a bargain really.

 

What difference in crown are you seeing? It seems to me that the classic straight lug models, Pro and FOIS crowns all have the same dimensions and a quick Look at MWO doesn't contradict this. AFAIK all Moonwatch crowns are the same size.

 

The FOIS crown has a thinner, slimmer profile than the standard Speedmaster Professional. The FOIS crowns are very close in dimension to the 2998s, though slightly thinner appearing than the 2998 crown. The thinner crowns of both vintage and FOIS reflect the straight lug case design that is free of crown guard case, thus no need for extra thickness to get beyond those crown guards.



After wearing a Speedmaster Professional for several years, I find the thinner crown refreshingly comfortable. Also seems easier to wind. If the slight difference between the vintage 2998 and FOIS proves bothersome, I think a swap to the slightly thicker 2998 crown can be made relatively easily.

 

I just checked and it is obvious you are right and the difference is quite marked. Shame. The thicker one does look better it’s true.

 

WOW!!! I was very much wrong about the FOIS crown. The CK2998 crown seems to be almost twice the thickness of the FOIS crown. I had no idea the difference was this apparent. This crown change by Omega seems very strange.

While I don't find a problem with FOIS thinner crown function, I can very much understand the FOIS mod to a thicker crown. I'm fine skipping any crown mods, but if I'd been going for a full CK2998 look, I'd have swapped out original bezel for a DON bezel. Also, I'd want to swap the crown as well.

Thanks for pointing this out.

 

Glad I found this thread. Definitely want to give this one a try = )

 

Now I just need to find someone in the UK prepared to do the job for me! ... Looks great!

 

Sounds great. Please post some pictures once you decide to take the plunge

I wish I knew who would do this in the UK. It definitely took me many months to find the guys here in the USA to do the swap. Dozens said it could not work, but that Aussie at Lewis Watch had proved it no problem. I was planning to ship it to Lewis Watch, because I didn't know they wouldn't do it unless it was their project.
Hopefully, someone will post a UK dealer that can put in the hesalite crystal. I personally love the look.