Let photos speak: Changed the comfy though very glossy silicon to a vintage rubber tropical strap. The 19mm width is not so easy for replacements/ alternatives. On below's shot you can spot the uneven sides of the hour markers, testimony of the embossed m...
Note that the true old-stock Tropics all seem to have curved lugs (as did the ones I once owned). You'll need flat lugged straps for this, so the $35 modern silicone should be fine. I'm using one on mine, and it's nearly as nice as the original NOS. The N...