A 98 sling w/keeper will work fine. In fact it's what you want if you use the sling for shooting. But it would not be technically "correct."
The Yugo sling fastens and "adjusts" at the end with a brass button.
They are listed regularly on Ebay and go for 15.00 to 25.00 depending on condition. Do an Ebay search and save as a favorite search. You will be notified via email each time one is listed.