Kelvin, Thanks for the response. I went ahead and ground down the offending tabs so that I could get the car running but now I know I can get a new circlip from Moss with confidence.
There isn't a lot of info out there regarding priming the oil pumps when they've been rebuilt (or at least completely drained). As I'll so share what I did to get my oil pump working again, in the off-chance it might help someone else:
1. The workshop manual is rather fuzzy on this subject. It only mentions, on page A.31, that a "special priming plug has been fitted to the cover to permit the pump to be primed..." But no instructions on how to do so. Also, while I have the highest regard for ol' Horst and his very fine "complete guide...." (my copy is practially falling apart from study) I couldn't bring myself to pack vasoline into my engine (oil pump) as he suggests to facilitate priming on page 94.
2. On my car, TD 25645, there is a brass plug on the top of the oil pump where the oil pump body connects to the block. It is just in front of the rear bracket for the generator. I took off this plug and used it to fill the oil pump with oil using a long necked funnel. I poured the oil in very slowly, constently checking to see if the cavity had filled up.
3. I took off the other two plugs that are lower down, but still on the top side of the oil pump. As I poured the oil into the upper hole I could watch the oil start to fill up those areas and just inserted them as the oil rose up near the threads. I think doing this helps air escape as the oil flows down into the unit but this possibly (pulling these two plugs) wasn't necessary.
4. I then cranked the car but noticed that oil pressure wasn't coming up so stopped. I had read in a string that one fellow had rotated his tires backwards to insure the priming oil was pulled down into the pump. As I had the radiator out of the car (a situation that anyone pulling apart their oil pump is most likely to find themselves in), I could simply use a socket and rachet on the main pully bolt to turn the crank counter clockwise. I did this about a full revolution or so.
5. Recranked the car and, presto, oil pressure.
Perhaps there are other ways to skin this cat but this worked for me. Hope this helps others.
btw, as I noted above, I have a rather late TD, so these priming plugs might not be on the newer cars. Also, if there is a better way to do this (on a late model TD), I'd really like to hear from you.
Thx, GA