Have just got an 80mm silver shutter lens with the same problem, but only below 1/30th.

Ebay seller was very reasonable and i've only paid about 20 for it in total now.

PJ Camera repairs in the UK have dealt with sticky shutters for me before, they're good value and turnaround is 2-3 weeks. They want 40+vat for the job. Fair price, but I can get a blue dot 80mm for 70 quid and the lens coating and flare resistance has been my main problem with the 65mm lens so far.

Now pondering if i should attempt repair myself, and if it goes wrong i have a lens board and viewing lens to use for a pinhole.