I was lucky enough to be able to take advantage of a strap offered by whoopy12. It is of the Isofrane type and very well made. The strap is fairly thick, very comfortable and is long enough to wear over a wet suit (if you are so inclined) The rubber compound used is very flexible and does not appear to be a dust magnet. The strap is completed with a fitted buckle , floating keeper and springbars. I think he has a few more available so give him a PM if you are interested. I recommend you do,he is a great guy to deal with!
Here are a few shots on my double grey 1665 (I am a pathetic photographer) They don't do the strap justice (it is dark black in person)