I think Randall's explanation about Bill's TS65007 is as plausible as anything. As for the information in the Moss Catalog, it's in agreement -- more or less -- with information I have:
TR3A
First car in calendar year 1959: TS41630
First car in calendar year 1960: TS65124
First car in calendar year 1961: TS82030
Note that it says "calendar year" in each case, so the numbers above are literally the first in each new year. This is not necessarily "in synch" with whatever a model year might be. Contrary to a seemingly popular belief, Triumph did seem to note model years somewhat similarly to how American manufacturers often did, with a change somewhere around mid-summer to the "next year's models" at that time. What I suspect has made so many people think otherwise (and for Moss and others to imply in quoting those numbers and dates as they do) is that Triumph didn't have the yearly styling changes of Ford or Chevy, and many changes -- even some significant ones -- were simply introduced when ready. And there's the whole "titled when first sold" thing.
Think about it: why would a dealer, or a manufacturer, want to be selling a "1959" model in late calendar year 1959 when all the dealers around him are selling the brand-new 1960 models? Given manufacturing and shipping lead times, it often happened that the current model year Triumphs didn't really start arriving here in the US until the calendar year. But if there were a few of "last year's cars" still lying about the dealership, and the ones about to arrive didn't look any different, it's understandable for both a seller and buyer to see that retitling to the current model year. That's probably why there are so many 1963 model-year TR3Bs, though production of that model ended before the end of calendar year 1962! (And I laugh to myself when some very early US Spitfire owners refer to their cars as 1962 models because they were made in that calendar year...especially since the US introduction was not until January 1963!)
Again, I don't have tons of charts and graphs and 8 x 10 glossies to back all this up, but "submitted for your approval".... /bcforum/images/%%GRAEMLIN_URL%%/wink.gif