David-

As you can see from these other responses, it's going to be very helpful if you can get some images of your paradox up on this discussion thread.

The most important images will be of the proof marks, which are located on the areas of the barrels and the action where they meet, sometimes called 'water table' or 'action flats' and 'barrel flats'
Also, there may be marks on the barrels forward of the action, on the sides of the barrels, or on the tops of the barrels.
Some guns/rifles have charge designations on the buttplate too.

One of my rifles has the charge engraved on the tops of the chamber areas of the barrels, and on the side of the action.
Some of my european rifles have charge information stamped on the sides of the chamber area of the barrels.

Give your paradox gun a good look-over. Photograph anything that looks like an intentional stamp or mark and put it up here on the thread.
Among the members of this site, there is likely the most complete, accurate, and generously available knowledge bases on fine/exotic/rare hunting and sporting guns and rifles on the planet.
If these men don't know for sure what to suggest, they know who to ask and will do so to get you pointed in the right direction.

If you can't get the photos done yourself, find someone to do it for you and do it soon so we can see your nice paradox!

We (and I can freely speak for the community here) truly would love to see this unique 28b paradox gun, even if only for the chance to view it.

--Tinker