Like many on this board I've been looking for a 10-string, probably directly as a result of encountering the great Hamilton De Holanda. I did acquire an electric 5-string, but the search for a good acoustic 10-string has continued for several years now.
I've watched the ongoing discussion as to the innovations and pitfalls of 10-string mandolins. Fan frets seem to be improving, with attention being paid to string guages, body size, etc. Conventional mandolin scale 10-strings sometimes suffer with floppy low C strings, or tight "pingy" E strings. Lots of experiments going on, but I've still been waiting for the magic 10-String to come along.
My goal is to eventually save enough money to buy one of Tercio Rebeiro's 10-String bandolims (since I love Ham's sound). He let me check out his bandolim, and I took careful measurements in case I decided to commision a domestic luthier to do a version of Ham's axe.
In the meantime I've been keeping an eye out for alternatives, and was excited to check out an Old Wave 10-String made by Bill Bussman. I first became aware of Bill's work when I saw Will Patton playing an Old Wave GOM (with great tone and playability). I also went crazy when I first saw Jazzmando Ted's Old Wave Solocomp.