Welcome here, Carlos. I don’t have firsthand experience with rubber straps for this model, but I was recently looking at the IWC website and saw that they have a very nice ‘strap selector’ function where you put in your model# and…
By: ArmisT : February 17th, 2022-09:16
it shows you the range of rubber (or other) straps specific to that model. I’m sure there are other aftermarket strap companies, but definitely check out the IWC site too. Good luck 👍🏼
while trying to find the rubber strap for IWC 3527. The issue is that rubber straps from that era have metal inserts which must match the grooves of the watch case. In my case the rubber strap from 3538 didn't fit 3527. IWC concierge wasn't helpful at all, neither was IWC boutique in NYC. IWC AD in las Vegas helped me to find the right strap. One thing to keep in mind is that if you buy a strap directly from IWC they are returnable if unworn and tags are intact.
It will be hard to find OEM rubber straps from that era...
By: India Whiskey Charlie : February 17th, 2022-16:57
Not only because they haven't been made for a long time but NOS might not be in good condition. That said, try these guys at Strapsco, they say out of stock which could mean entirely gone or just waiting for a new shipment.