The easiest to tell what model it is (without checking engine numbers) have a look at the top of the handles. If it has a chrome bar for the clutch. It is a mark III if it is a plastic handle for the clutch it is a mark IV. As far as being hard to find. Yes they are getting harder to find. No not rare just losing them as they are at the point that people just throw them away. Yes I do have all four but it did take a while. Especially the mark I they are really hard to find.
