When tried the first time, it did not focus correctly so it went into a box, and I forgot about it. Recently I found the lens, tried it again to see if it had corrected itself (it had not) and sent it for adjustment to my technician, who did a good job. Although the rangefinder coupling is way off, now it works nicely with scale focusing.
A trial, mounted in my Leica III with HP5+, went well enough. It is a convenient focal distance for general subjects, and the lens is compact.
Happy to have recovered this lens, and now I am intrigued about the Tenax II….