Recently acquired this unique beauty from the 90s. The problem is the titanium bracelet is too short and I need at least 4 links (22 mm width). Quick search on the bay showed one listing with only 2 links with an absurd price IMO. I thought about a buckle extender for the double deployant buckle but can’t find anything compatible. Another option is a leather strap conversion but can’t find anything compatible either. Suggestions?

Edit: Further research point to this being a first generation ref 3700 from 1979-1980 before both companies (IWC and Porsche) agreed on specifics of the watch.

 

This is a tough one.

Have you tried to write to IWC? They have a section in their site and a blog dedicated to the Porsche design watches.

The first generation titanium bracelets were known to be very feeble, and most of them had to be replaced in the Ocean 2000, Ref 3500. I supposed there has been a similar need in relation to your model.

Good luck.

 

After a prolonged search for additional links and a proper crown replacement, I can now finally wear this unique first generation ref 3700. Thanks to @Time Exposure for shedding light on this often overlooked reference. Apparently this is the first iteration of the world’s first titanium chronograph. The first 500 examples have an engraved number A-xxx above the serial number on the caseback (A-001 to A-500). These were engraved by Tourneau who was IWC’s agent at the time.

 

The world's first serially produced titanium watch with integrated bracelet. Other watches (Citizen in 1970 and Seiko around 1975) produced a limited number with titanium watch cases. Omega produced five prototype Speedmaster chronographs for the NASA Alaska Project in (1968? 1969?) but you'll never see one of those!
IWC made titanium a viable material for watches, and others followed suit. That's why you'll see "TITAN" engraved on the 6 o'clock links of the early models up to around 1987. By 1988, titanium as a material for watch cases wasn't so exotic, and the "TITAN" engraving was dropped. Yours is among the earliest. It's rare to see the original dial (which only mentions IWC) along with the link below TITAN engraved "PORSCHE DESIGN." So many watches from the earliest days were updated with new parts when they were sent in to IWC for service.
See if your watchmaker has a black-on-white date wheel for the 7750 that fits your Titan. Then yours will look like a period-correct example! Even if it won't match the rest of the dial...I think that's why the white-on-black date wheel quickly replaced it.

 

These early collaborations between IWC and PD are fantastic, and probably under appreciated which makes them quite affordable. I still hope to find a bargain Ocean 2000 one day.