Skidder,
You did get a good deal on yours, probably at least the equal of the score madwell got. The key difference is yours is "pre Mk III". Yours is hand fitted, with the Mk III series Colt re-racked the balls entirely and re-engineered the entire action with an eye toward manufacturing cost reduction. This did not produce "junk" just that to collectors (and discerning shooters) the value of the pre Mk III's is higher and they pay as such for them. I have owned 3 of the Mk III's, a 4" Trooper Mk III, a 6 " and a 2" Lawman Mk III and am sold on them. Madwell paid less than I ever did.
The Trooper you bought is a different animal entirely. With the hand fitting and all forged parts it is in no-ones opinion the same or inferior, to most superior. They are also getting more scarce than the Mk III's.
It isn't the same action just not hand fitted, it is different entirely and not to be seen again. Neither will the Mk III's come to think of it.