I would say that you found your problem :D. It's always a good thing when you find the problem you were looking for. Good call with the oil pressure gauge install. Having the guage probably saved your engine from being trashed when your pump went out. The new oil pump gears and timing kit should really help out. I'll cross my fingers and knock on wood, but I bet you'll have a good running, "TICK free" rover when you get it back together.

Don't forget to:
-prime the pump with grease or vaseline before putting it back together (don't over pack the pump it could clog).
-pull the fuel pump relay and crank it a few times to draw the oil up into the pump before starting for the first time.
-As always, fill the oil filter with oil before install
-the crankshaft pulley bolt needs to be torqued to 200lbf.ft

Your doing a great job, keep up the good work.

Before resorting to pulling the pins, remove the front oil seal from the cover, and re-assemble the cover to the block and lightly torque the bolts. Using one of those magnet on a stick devices, feed it next to the crank snout and grab the inner sleeve of the rotor (inner part of the pump gears) and see if you can easily slide it forwards and backwards on the crank. If it is even slightly tight, then it is sure the pump is being loaded radially (by poor location of the front cover) and will likely fail again.

Basically, you want to rotate the crank a full 360 and just check that the pump feels "free"... any sign of tightness and binding on the axial float test, and it will benefit from some attention sent the way of the dowels.

BTW - if the dowels are mis-aligned, you'll notice all your bolts holding the cover to the block will be biased to one-side in the bolt-holes (very visible with the cover on the engine and the screws screwed about 1/4" out).

It does appear that all pumps "can" fail - even on non-2003 models, so that is why it is worth checking the pump "float" on any model / year...

Thanks! I will do some testing to make sure it isn't binding. I worry about pulling the pins completely since the tension from the belt moving it.

If your gears were cracked like that I would pull them. Some of them were drilled in on an angle causing pressure on the gears. The only thing they are there for is to help with alignment. Just make sure that you have the gasket on there properly and you torque in the right pattern. I agree with turbo dave, you cant go wrong with doing some extra checks, but like I said regarding the gears in the picture, if they are cracked like that then you definitely have an alignment issue. Your call, just giving you another option.