I chose the 103 ST largely because of the retro look and feel, with it's tall acrylic crystal; it took me back to a time when I lusted for watches that looked like that, but had no money to buy with. It made me feel 13 years old again (but without all the angst).
Still, something was out of whack. The strap just didn't go with the rest of the package somehow, but I couldn't seem to find the right one to take its place. Then it dawned on me - I already had the answer sitting in a drawer. What better to complete that retro look than a strap from "back in the day"? The answer was a NOS Sub Tropic strap. I have some I bought for vintage Zodiac Sea Wolves, 18mm versions, but also a couple of 20mm-s.
As it came, on the Sinn leather chrono strap:
On the Sub Tropic:
I think the Sub Tropic does the trick for me; not only does it complete the late 60s look, but it's a tad longer and more flexible too, which makes it more comfortable.
Of course the downside is that sooner or later straps wear and need to be replaced, and they don't make these anymore. It's a shame that no one has picked up the torch and made modern versions of these and the basket weave Tropics.
Not a big deal, I admit, but I'm digging it and wanted to share. An under $50 strap that changes the whole look; talk about a cheap makeover.