Recto 2 is a Dual Rectifier Reborn Multi-watt (mid 2010s), it's the latest revision of the dual rectifier preamp circuit and closest to the Road King and Roadster.
The Road King and Roadster are darker than a Dual Rec, but as far as the preamp distortion goes it's pretty spot on. The presence pot tapers on the respective amps are going to be different as well. On Recto 2, try getting the distortion how you like it with the gain and master first, then slightly adjust the Xformer High Freq down a little until the high end smooths out the way you remember, then adjust Power Amp Tube Mismatch up or down ever so slightly (+/- 0.250 is all it takes, the effect is blatantly noticeable as early as +/- 0.050).
One thing worth noting too is that the gain knob does a lot of filtering on it's own, the lower it is the brighter it gets. It helps a lot to turn the gain knob till it sounds right (with all the tone knobs at noon) and then adjust input trim (essentially a clean boost on the input) to increase the distortion to the desired amount. It's a push pull with the gain knob and tone knobs, you can run the gain really high and get away with higher treble and presence settings, where if the gain was lower those treble and presence settings would be too harsh.
There's a lot of weird interaction between the tone knobs on a recto. At some point if you have bass back about 10 o clock, and presence past 5 o clock, increasing the bass up to 2 or 3 adds more high end in the top. They all tug and push on each other in a weird way.