man, try these before anything else.

Leapers UTG Dovetail to Picatinny/Weaver Cantilever Base Rail Adaptor MNT-DTW145

or

Scope Rail Converter 11mm Dovetail to 20mm Weaver Low Rail Mount - UK Seller

they both work on my hw100s. No issues. with the last one I have 1mm between my scope I think it is 50mm front objective and the barrel. no way you can get lower.
of course you can match the rings.