If the oiltank is still off, prime the feedpipe leading from the tank. Kicking the engine over with the plugs out should see the oil happily disappear into the pipe, as the primed pump draws it down. With the PRV removed, oil should appear from the central hole in the crankcase as the engine is kicked over. Feeding oil into this hole with a pressure oilcan will force oil into the oil gallery running around the back of the timing bush, and then to the bush bearing surface and on into the crank and big ends. The anti wet sump valve should prevent back flow to the pump.
If the tank is back on and filled with oil, air pressure on the vent pipe, oil cap on, will pressure feed oil to the pump. A little bit of kicking should see oil at the PRV cavity.
Once the engine is running, it takes a few heart in mouth moments before oil will return to the tank, as this side of the system is effectively empty, but introducing oil into the return pipe before replacing the tank, or if the sump plate is off, pumping oil up the pick up pipe will give the return side of the new pump some initial lubrication. Julian's suggestion is another trick, easiest is via the rear rocker cover.... stick a good amount of oil down here anyway to bathe the camshaft and followers.
Depending on how much oil is in the sump, the oil will either gulp into the tank to start with as air and oil are scavenged, or be a continuous stream. Once things settle the oil stream will vary between a continuous stream at high engine speeds, to a gentle gulp as the pump scavenges air and oil at tickover. Oil to the rocker gear will appear late in the proceedings, being fed by the return from the pump.
Avoid excessive periods at idle speed to start with, modern expensive oils have anti wear additives and this can result in poor ring sealing. Cheap oil is fine for running in.
Swarfy.