Would you care to share your clone recipe of Ballantine?
I intend to do that, definitely.
In the meantime, the formula given in the recent BYO article looks to be a fairly good starting point and is remarkably in sync with one of the recipes I came up with independently. Which brings me to...
The only problem I have in posting my own take on it really is deciding which one to post...I've played around with formulas for this brew for a very long time (the original was in fact still being made when I first started to try and clone it). As a result, oddly enough I have come up with at least 4 distinctly different formulations that (to me anyway) come very close to the character of the brew that I drank so much of in the late 60's/early 70's. Some of the experiments stay fairly close to what I have been able to turn up about the original beer, and other stabs at it definitely stray from the original formula and yet still manage to recreate the character pretty convincingly.
However the two constants (and absolute musts) for truly recreating this beer, are the year of aging and the combination dry hopping and dosing with distilled aromatic hop oil that happens in the final month or two of the long aging. It still impresses me that a large brewery gave so much attention 40-50 years ago to what was certainly a niche product for them...and that the new commercial brewers have only fairly recently turned attention to proper, long aging of certain beers.
In any case, I am also working on an extended and fairly in-depth piece that discusses this beer at length ...hopefully it will find its way into print somewhere eventually.