It's not a Contender part it's a Weaver 92A scope base.

If your barrel is a straight barrel with no taper this base will work as is. If you have a tapered barrel you might have to fit them.

I recently mounted a scope on a BSA 1215. Without modification to the base the rifle shot 12 inches high at 25 yards. There was no where near that much adjustment in the scope. The problem was that the barrel was tapered and the base was aligned with the taper of the barrel and not the bore.

There is a quick and simple way to taper the base. You need a piece of 320 grit wet dry sandpaper and couple of spring clamps.

Wrap the sandpaper around the barrel over the scope mount holes, clamp the paper tight with the spring clamps. Set the base over the area of scope mounting holes on the sandpaper and slide it up and down the barrel 1/2 to 3/4 of an inch. Apply uniform pressure and sand lightly. Be careful not to tip the base or apply uneven pressure to one side of the other. Check the base to be sure that the sanding down is even.

Check the fit on the barrel frequently. I found on this barrel when the base fit front to rear on the contour of the barrel it was just right. It may take some cut and try by shooting for other barrels depending in contour. What you want to achieve is getting the top of the base parallel with the bore.

Works for me.

If you can't find a Weaver base down there let me know. I'll send you down one. You will also need scope rings that fit a Weaver base. Weaver rings of course or I like to use Millets rings you gan adjust for windage using the clamp nuts. I can send you a set of rings also.