Well, thanks for all the nice comments, and I'm glad we got the video sorted.
The instrument is surprisingly easy to play. It is a very small theorbo, with a fretboard string length of 69.3cm - big Italian theorbos can reach the high 90s. The French came up with a small theorbo of around the mid 70s for the short strings, so this one is smaller than that. Castaldi, one of the important theorbo composers, invented a tiorbino, with a short-string length of only 50cms, tuned an octave higher than normal. But Castaldi is also pictured playing one about the same length as mine.
As for strings, plain gut sounds best on the huge Italian theorbos, but not so great with the shorter lengths. At the moment mine has Kurshner wound basses, similar to classical guitar basses, but they are very old, and have therefore lost some of their sparkle. This might be the best solution - old wound strings. As they are not fretted, they can last for years. I'll admit I'm a little unsure how to string it, but at the moment it sounds good. The first four strings are nylon, and feel too thick, especially when doing slurs and trills, so I might try gut or nylgut there.
Anyway, it's a bit of an exploration for me, and great fun to play. There is a lot of repertoire, with the main names being Picinnini, Kapsberger, Castaldi, and Robert de Visée, who wrote many beautiful suites for it. On top of all that, contemporary composer, Gilbert Isbin, has already started writing new music for me. So, this is not a one-off video. There will be more to come.