JMO, but even if some clamp-on scope mounts could be found, I don't think they'll hold on a .454 Casull.
If the rear bbl sight dovetail is approx 4" from the front of the receiver of your M92, a scout scope can be mounted in Weaver-type rings with the rear lens just ahead of the EJ port via installing a short XS LeverScout mount meant for the Winchester 94.
The front of the XS mount is anchored in the barrel dovetail, the rear needs two 6-48 D/T'd hole in the top of the front of the receiver, inline with the bore.
Another possible alternative, if your Puma has the lawyer bolt safety, is to replace the safety with a bolt paap sight.
It can be a surprise to many who think "scope", that a peep sight will do.
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