A few years back I decided I wanted to scope my 512 Sportmaster too. There were many of them made, so I wasn't worried about the collector value of it.
Once that decision was made I obtained two Weaver #43 scope bases and had my local gunsmith drill & tap the receiver and mount the bases for me. The scope bases were about $12 and the gunsmith charged me $50 for his sevices. The Weaver #43's are the ones that will fit your 510 too. Some folks have used JB Weld or Locktite-Black to glue them in place too with good results.
After that, getting a scope and rings installed by myself was easy. I used some 1" B-square, medium ht. rings with a 1" offset on the rear ring to provide bolt clearance. It all works great and I'm really happy with the results.
Here's a picture: