Here is a video I just made about how to fix one of the common failure points of vintage Gretsch micro-sensitive snare throw offs. Not the slickest of productions but you should be able to get all the information you'd need to do this fix if you have a similarly afflicted drum. The required part costs less than $5 and should be readily available most anywhere.
Hope this might be of help to someone...
[ame="https://www.youtube.com/watch?v=D8j9FBCh_sw"]Gretsch Micro-Sensitive Throw-Off easy fix - YouTube[/ame]