Was finally able to locate and mount a single saddlebag for the left side of my Scrambler - I used the left half of River Road's Model: Classic Quick-Release Compact bags. I was able to buy the saddlebag bracket only from the Triumph single saddlebag kit that had previously been available for the Scramblers - then a visit to the local leather shop to fabricate some straps that attach to the frame under the seat and I'm in business. I like the look and though I was afraid the bike would look awkward with only one bag, it actually is nicely balanced visually by the high pipes on the right. The bag is "pleather" - not real leather - but comes with a nylon rain cover and is large enough to hold some rain gear and a small tool kit without being too large. The bag measures 15.5" W x 10" H x 5" D, and comes with an interior removable liner as well as the rain cover.
I have the right side bag available if anyone else is interested - will let it go for my cost ($60) plus shipping - only problem would be that the extra pocket on the outside of the bag (at the rear of the bag as shown on my bag) would be on the front and might interfere with a passengers left leg. PM me if interested and I'll share the details.