Agreeing with you. An early version with grooves in the forend proved most accurate in my hands with some humble Marksman pellets (which they have improved and still making bytheway) I also got to shoot an even earlier version with very slim stock with same results.
The barrel looked pretty decent, with nice crisp rifling grooves in the pellets and no tell tale clippings coming off the loading tap. Must have been aligned quite well. The gun balanced well.
General performance better than a BSA Meteor, perhaps matching a Mercury was my assessment 35 years ago..