difference in NA vs NB rear upright

So, replacing a rear axle on my 99 miata has been much more of an ordeal than expected.

I couldn't get the axle out of the hub.  Took it to a shop, and they broke the cast upright in their press.

Got a JY replacement, that wound up being from an earlier model car.  Everything is back together.   Seems to drive ok.  But apparently, there is a 5mm difference in the wheel offset with the older style upright?  As in the track is 5mm narrower per side on the old style.  Just eyeballing it, not apparent that the one wheel sits different than the other.  

I can get the correct part off ebay for $100.

This car has the Paco lift kit on it, and in the current chapter of its life, I use it for going to mountain bike or find hiking trails, so just cruising, not really important to have totally dialed in handling.

I'm kind of sick of working on this car and spending money on it.  How bad an idea is it just to drive it as is, and not install the correct upright?

I did it and did not die.  Never noticed it while daily driving the car.

Personally, I would fix it.  Axles come out pretty easily when they're new, it's only after it's had 20 years to corrode in place that they stick like that, so it shouldn't be more than an hour or two to swap it.

You know what the right answer is. It’s up to you to decide if you want to put in the time and money. 

Interesting... I never knew that the NB’s had a wider track in the back.  I swapped a Torsen into my ‘92, and also couldn’t get the axles out of the uprights.  I just used the NB uprights, and I’ve never noticed a difference.