Well, I think it's done. Trim Tab number 2 is a success!
After fabricating end-caps, it was just a matter of assembling, aligning, trimming, cleco'ing, measuring, triming, etc. etc. In retrospect it wasn't that hard, but it certainly set me back for a while. Just glad that I can now move on.
By far this has been the most challenging aspect of the kit so far.