Will,
I am not quite so far up the coast as Ian is, being in SE Pennsylvania.
I have a Mark 3 Sports, for which I got a replica narrow center stand from The LDMCC years ago before the embargo. I can attest to Ian's comment that they tip over easily with the original style center stand! Eventually I welded on wings and add little to the height to try and make it more stable, but on soft ground I find it more reliable to lean the bike against a tree, fence, or a wall!
Originally the bikes were not fitted with a side stand, and no provision was made for that option. So various folk have exercised their ingenuity to adapt mounting points to add a prop stand. There have been examples of such posted on this forum.
-Doug