When I was a kid, my best friend had a fixed power weaver K-10 mounted on a .222.......It was certain death on groundhogs.........I'd say that classic scope would be perfect on that classic rifle......
I also have a friend who has one of the old Unerlt on a ruger no 1 in a 22.250........seems his is higher powered than that, and I'm thinking it's a 15X..........Another friend has one on his 6mm Gibbs........
I've been watching ebay for awhile as I've always wanted a Unerlt from the time I was a kid, and would still like to have one.......
There's one for sale on Ebay now and the current bid in $550, but I've seen them go for a lot higher than that and I would guess $700 wouldn't be out of the question.........if you have all the accessories it could even go higher......
Antiques are hard to put an exact value on.......and really depends on how much someone is willing to pay........
http://cgi.ebay.com/J-Unertl-10-X-Target-Var-rifle-scope_W0QQitemZ7199762594QQcategoryZ31714QQrdZ1QQcmdZViewItem