The quality on these Mausers has always been excellent, since Interarms started importing them as the Mark X in 1970.
They were sold by Interarms as complete rifles with a couple different stocks as well as barreled actions for custom and semi custom Mausers. The had a tenite tipped white line trimmed stock along the lines of the Remington "C" models. The checkering was pressed but it was nicely pressed and the walnut was generally quite nice. They also had a more classic looking walnut stock.
The early MK Xs, have a more traditional commercial Mauser style floor plate release, while the later Mk Xs switched to a cross bolt button release that is still in use today.
The M85 was added as the Mini Mark X in 1985 in smaller calibers like the .22 Hornet, .222 Rem and .223 Rem.
Importation fell off during the arms embargo in the region in the 1990s, but after Interarms closed it's door, Charles Daly started importing them as the Charles Daly Mauser and Mini Mauser with composite stocks.
Remington then started importing them as the Remington 798 and 799 respectively from 2006 to 2008. Remington used a slightly shorter barrel - 20" versus 21.5" and they used a laminated wood stock with fairly modern lines.
CAI now imports the rifles as the Zastava M70 and M85. The finish on the stocks is not impressive, but as noted above a little Tung Oil or Tru-Oil on the stock brings out the quality of the wood. The checkering also benefits from some finish work.
However, the metal work, polish and bluing on these rifles, under what ever banner they were imported has always been impressive, and I've only owned one over the years that has not been capable of MOA or sub-MOA accuracy.
My first as an Interarms Mk X rifle in .243 Win and it would consistently print 5 shot 1" groups at 100 yards with both 87 gr and 100 gr Hornady's.
My next was a Mk X barreled action in .308 that went into a Bell and Carlson stock and it was also a consistent 5 shot 1 MOA rifle.
My last three have been Mini Mausers - a pair of M85s, one in .22 Hornet and one in .223 Rem, and a Remington 799 in .22 Hornet. Both the .22 Hornets are sub MOA rifles (1/2 to 3/4 MOA), but the .223 struggles a bit with 5 shot groups in the 1.5 MOA range. I suspect it's barrel wasn't properly stress relieved as consecutive cold barrel shots give sub MOA accuracy.
Zastava has always used hammer forged barrels. They offer a very hard and very smooth surfaces that wears well and collects very little copper fouling, but the hammer forging process imparts a great deal of stress, so proper stress relieving is vital to stability as the barrel heats up.
Below are my Zastava M85 (middle) and Rem 799 (bottom) with my Browning 1885 Low Wall, all in .22 Hornet. The Mausers are in Interarms stocks that I acquired new in the box from Numerich Arms, who had gotten all the old stock from Interarms. However, I bought the last three they had.
Below is my Rem 799 in .22 Hornet in the Remington laminated stock: