86 MM oil pump clatter: to change the pump? or not to change the pump?

bought this 86 mm 2.0l 5 speed a few months ago. Had a broken B timing belt, a busted B tensioner, and ball bearings loose in the timing case. The B crankshaft balance shaft cog was damaged by the ball bearings so i had to get one from the junk yard. When i was investigating whether to try to salvage this engine, i repaired the timing belt situation and got it running pretty well. It had a badly cracked exhaust manifold, and some missing exhaust manifold nuts. it had a crappy empi weber clone on it that was dripping gas into the manifold so i found a real weber on craigslist and fixed that mess.

As I've fixed the timing belts and exhaust (extracting broken manifold stud, replacing head gasket) got it tuned nice and running good with a smooth idle, steady vacuum and nice and peppy.

One consequence of the newly repaired exhaust is now i can hear a noise coming from my oil pump. It's kind of a little clatter when the engine is cold. Once it warms up it goes away.
How do i know it's the oil pump?

I just took off the timing cover and have been inspecting the oil pump. It has some play in it, so that when i turn the sprocket nut back and forth with my fingers I can feel play between the pump shaft and whatever part of the internal pump has play in it.
Also, when i apply some force side-to-side on the shaft, it moves a little bit.

My question is: what's the prognosis on this? can i run it this way for a while? 20 k miles? or is this something that indicates its coming apart?

I'm concerned that once i open this up it's going to cascade into a lot more stuff than i can handle right now.

Just wondering what the forum has seen out there with these pumps and was wondering if a little play and wear is normal for g63b with 100k miles.

P