Wilf,
It would seem that there were 2 versions of the steel dipper tray prior to the cast alloy version. I have seen steel dipper trays with just the 2 troughs for the bigend splashers - others also have an extra trough across the back of the tray, which presumably just retains some of the oil that is thrown up.
Whereas the earlier models had a branch in the main oil line that fed oil direct to the dipper trays, the later models (with the cast alloy dipper tray) relied solely on enough oil passing through the sight glass to lubricate the whole motor. Having got that much oil into the motor, there was no way of returning it to the sump, as the alloy tray sealed the crankcase floor.
With this lubrication system, the LDMCC machine has had at least 2 cranks in the last 10 years, along with several instances of inadequate lubrication on the back cylinder. The committee took the decision that we should revert to the older system as this seems to be more 'user friendly'. So that we didn't make any irreversible modifications, I made a new dipper tray with drain ports to return excess oil to the sump, a new feed pipe and elbow that screws in behind the flywheel, and a new main oil feed pipe with the necessary branch. As I said previously, we now just have to test and adjust the new setup until we get reliable running without too much smoke!!
Regards,
Eddie.