This is the long list of all known original Lucas distributors (and specifications). Click for 20-page 159-KB pdf file.
lucas_distributor_specs.pdf

There will be some confusion when refering to the direction of rotation of the distributor. Lucas technical manuals go to some length to note that distributor rotational direction is as viewed from the driven end. That being the case all MGA (including Twin Cam) and MGB disributors have clockwise rotation. However, most of us mechanical types who need to service the car regularly will most often be looking at the top end of the distributor, in which case it turns counter-clockwise (as noted in the chart above).