All but one of my NEF/H&R products wear 20 mm scopes. This is mainly done as a surefire way to get around clearing the top of the hammer. Presently all I use are the Leupold 20mm (1-4's-1.5-5's) and the Weaver 1-3's. These will fit on everything I own plus fit me and my son well. We seem to always come back to them.
Recently tried to fit a Bushnell Banner 1.5-4.5 x32 mm on a Topper and gave up and went back to a Leupy 1-4. As you know the Leupys cost more than the NEF/H&R products I put them on. Awhile back I did pick up two used VariXIII's for a song, but deals like that don't seem to be popping up anymore. The newer Weaver V3's appear to be different as the eye relief is now at 3.12" versus the 4" it was on earlier ones where the "Weaver" inscription was in white lettering on the side of the turret housing. Don't know if the Weavers are still Japanese made or not.
Question, what else is available out there that you have used that is not super expensive with a small ocular bell and in 20 mm objective? Thanks for any info you might have.