Yep, 6-10 pumps means air is getting in somewhere. Priming the system to get started should be fine for a while, however air in the fuel is not good for your injector pump in the long term, so I would try to get it sorted fairly soon. Is there any sign of diesel leaking? Let the engine idle for a minute or two, then have a good look around with a torch especially around the injector pump and injector lines. Next, I would definitely recommend getting about 4 of the clamping tools I mentioned. You should be able to pick them up from any auto parts place for $5-$10 each. Preventing as much air as possible from entering the system when disconnecting or replacing fuel hoses or changing the filter makes a big difference when it comes to priming and restarting the engine. If all your flexible fuel hoses have never been changed, they are probably hard and brittle, so it would probably be worth replacing them. It's also inexpensive and not too difficult, some of them are a bit fiddly though- especially getting the clamps on. You might consider replacing the original spring clamps with worm drive ones but be careful not to over tighten them. If that doesn't fix the problem, I would try pumping the primer up hard as soon as you shut down, then clamp off the hose as close as possible to the filter outlet and leave overnight. With the clamp still in place, pump the primer again. If it still takes 6-10 pumps to get hard then I would suspect the primer.
Hope this helps, keep us posted on any progress.