This area needs a long overdue tidy up both in terms of updated data and removal of the many double up distinctions. The LH horn mount gets mentioned around 3 or 4 times by way of example. Also, the fat exhaust clamps are mentioned a few times. This is not being critical as I have contributed as much as anyone to this section, it's just time for a critique and update.
I've reviewed and amended/updated a number of distinctions tonight and several more need to be looked at. I've also added some riders on some distinctions as there is new evidence coming to light every year and we need to just add some clarity. For example the thin lip 9 hole cover was stated to have been fitted up to around frame 800. Well, I've seen many later engines with thin lip 9 hole covers in recent years and a good example is E1788 currently for sale on eBay. Again this is not a criticism, just updating the information we had when the knowledge base went up. I'm sure there are later engines out there with a thin lip 9 hole cover.
Given the ownership coverage of known original sandcasts by members, I would ask owners to review the list on this site and advise any things that you believe need to change. One area not on our list, and I believe it should feature, relates to instrument drives. We know there are at least 3 types of sand-cast instrument drives however the frame number changes would be good to know, given the expense of these things in recent years. I have views on this but little in the way of actual evidence. A pictorial reference would be even better. I volunteered to do this many years ago and I've provided numerous photo depictions of those distinctions over the years but more contribution is needed. I don't own enough parts or machines to photographically identify all these distinctions. Help with this is needed.