Thanks to Andreas Hartmann-Virnich, for some great pictures of his ca. 1800 Border pipes. These pipes are up and running and being played. Here's what Andreas had to say about them, "They have very slender proportions, as slender as my David Glen miniature pipes, and they produce a somewhat thinnish drone sound with rich overtones. The tenors are both authentic but have different lengths (like several of my early GHB’s) and are difficult to reed. I believe that this difference was intended to produce a combination of two different sounds instead of a mere addition of two identical drones. Sadly this feature was disused after ca. 1850. I find the style of the ferrules particularly beautiful as they combine both bone and black horn. The button mounts and drone tops are marine and elephant ivory. Hugh Cheape suggested that it might be a Hugh Robertson set due to the tulip style of the bass. The difference in style to the tenors is intended."

The idea of two different tenors makes perfect sense to me, and is something I'll try out in the future. Also, the contrasting black and white "ferrules" is something I've never seen before, maybe worth a try on my pipes.