Make sure you're getting an actual Leupold, and not a Chinese copy first. Easiest way if you don't know is to call Leupold customer service and give them the serial number. They (at least used to) track fakes. I did this with a ca. 2000 Mk4 10x with M3 adjustments that came on a first gen FN SPR rifle before I bought the setup. The local shop told me it was a police trade-in, but I wanted to make sure and not trust a story before I spent my money.
I still use my Mark 4. It still sits on that SPR. The adjustments are mushy as hell, and I can probably fix it, or send it in to Leupold to get it fixed. You can't tell by sound that you've made an adjustment, just by a faint tactile feel...good luck if you're wearing gloves.
I shot one box of FGMM 168gr when I got the rifle. It was zeroed perfectly for that load, and the M3 turret is marked for FGMM 168gr. It produced a couple of. 8-.9 MOA five shot groups if I remember correctly. Nothing fantastic, but I remember being satisfied.
I've since skim bedded and Krylon'd the HS stock, and decided a few years ago I'd dick around with making it a bit of a hunting rifle. I've mentioned it elsewhere on this site; but my very first load I tried, I used the 165gr Nosler BT and put five rounds into .419" at 100 yards. Easiest load development ever. Plus, I'm really lucky in that the Nosler handload tracks perfectly to 400 yards on that turret. It's mushy as hell, but repeatable.
Three years and four bucks later, and I'll be pulling it out of the safe again come November. However this time it'll be sitting loaded next to my side door as I've got a different rifle in mind as my primary rig. However, I've not lost a deer to my combo, and my couple check shots at 250 have always been right on the money. This is why I've never screwed with trying to get the mush out of my turret.
I also have a newer 10x SWFA SS. For $300 it is pretty repeatable and the adjustments are close. I'd also be willing to bet that the glass is pretty comparable to a Leupold Mark 4 from two decades ago (I'm sure more current examples of the Mark 4 are better). I wouldn't recommend it for a hunt of a lifetime at all, because decent mid-tier glass is going to give you a few more minutes of shooting light. But for a bargain rifle or just target shooting I'd say go for it.
My bottom line...I think that the 1997 made Mark 4 and your SS are going to be closer than you might have thought.
My example: