I have the Tower Type 3. It is slightly smaller than my Leica IIIc. Mine works extremely well and is very, very smooth in operation. I have the Nikkor H 50mm f2 lens, which is very good, but a bit heavy. It is a coupled rangefinder and mine is extremely accurate as well with the 50 and with the 35. I have not tried anything any longer with it yet but I suspect it will respond fine with my 90 as well.
Mine does not have a flash sync port but based on the serial numbers mine is likely a bit older than yours. Mine is 34xxx. It is my understanding that some of these have a synch port and some do not.
Youxin Ye recently did a full CLA and replaced the shutter curtain which was rotten and pinholed.
I love working with mine. I have been shooting Efke KB25 in it most recently. I haven't printed or scanned any of the film yet but the negatives look good. I'll run some of this through the scanner this week and post some of it so we can see how the shots turned out.
Interestingly the Nikkor H 50mm f2 lens seems to be very, very good. I used my M9 to do some side by side shots of my refrigerator using this lens and some other 50s I own right now and it seems to hold up pretty decent. It is not quite as nice as the Zeiss Planar 50 f2, but it is as good or better than some of the others I have. It definitely out shoots my Nokton 50mm 1.1 at f2.