I might be burned at the stake for saying this and this is just my opinion but I think that the Peterson Elizabethan Mixture is significantly better than the Dunhill blend. I can taste much more of the perique and Va that I did with dunhill, granted, I have only had one tin when it was still under Dunhill.
If you're referring to any Dunhill blends made in the past 15 years, they were made by STG under license to BAT, the holder of the rights to the Dunhill blends. Around 2018, BAT decided to stop allowing the Dunhill blends to be made.
STG also owns the Peterson Tobacco IP, so when they finally negotiated with BAT to resume making the Dunhill blends, the only change was to the tin art, with the Peterson name being substituted for the Dunhill name.
Same manufacturer, same pipeline, same people overseeing the production, same tobacco stocks.
Given that sources have been more markedly changing over the several years, it's possible that some components going into those tins have been swapped due to availability. But it's the same company and facility making what were the "Dunhill" branded blends and the "Peterson" branded blends. Dunhill hasn't made their own tobaccos since about 1980.