Thanks Mike, as it happens, tomorrow a relation will bring me a bottle of Four Roses Single Barrel 86 proof, sourced recently in The Netherlands. This is the version that was marketed in Europe from (at least) the late 1990's - of course regular Four Roses bourbon was available for decades earlier in Europe, and therefore well before its re-introduction here. This 86 proof version of the SB was later withdrawn at least in the U.S. but I think also in Europe, to be replaced by the 100 proof bottling. The 86 proof export version is in a flask-style bottle (a flattish, slope-shouldered bottle). I'll post a review of this one soon.
More notes on the export 86 proof: this is the bottle pictured and described in BE list of whiskeys (for the whiskey reviews on this site) as "Four Roses Single Barrel Export". Interestingly, a similar whiskey, but in a different bottle, also described and pictured in the BE list, was sold in the same era in the U.S. (late 90's, early 00's). I haven't tried that U.S. bottling but would assume it is the same as the exported version. Of the others on the list, I've tried the Black Label one (an export to Japan) and thought it was good, not great. The Super Platinum one, also sold in Japan, has eluded me so far, I understand it is very good.
I guess what I want to see is if the profile of the late 90's-early 00's FRSB Export is the same as the current 100 proof, with the only difference being the reduced proof. We will see.