Just in case anyone is looking for a reasonable oil pump rebuild kit, British Pacific has it but you have to search. It's not listed under the D1's oil pump section. Strangely, it's only listed in the Defender 90 section.

Land Rover parts, spares, Land Rover accessories - Search results for GPK001

 

Don't forget you also need a front cover seal and a crank seal as well as checking and possibly replacing the timing chain and gear set.

 

Oh the other BP, not the oil spill guys.................

 

You can get them for less on eBay. I'm pretty sure Paul Schram has them as well for less.