Mark-----
They were not too rare once-upon-a-time. However, most of these things went into the trash can years ago. Outside of a few specialty rebuilders that have come online in the relatively recent past to serve the restoration market, the clutches were never commercially rebuilt or considered to be rebuildable. They had no core value. Fan clutches were often the first thing to be replaced, and rightfully so, if an engine had idle cooling problems. Fan clutches, especially those of the 60's, actually had a fairly short useful life, probably no more than 50,000 miles, maximum, in most cases. So, most of those that "once were" are no more.
They were not too rare once-upon-a-time. However, most of these things went into the trash can years ago. Outside of a few specialty rebuilders that have come online in the relatively recent past to serve the restoration market, the clutches were never commercially rebuilt or considered to be rebuildable. They had no core value. Fan clutches were often the first thing to be replaced, and rightfully so, if an engine had idle cooling problems. Fan clutches, especially those of the 60's, actually had a fairly short useful life, probably no more than 50,000 miles, maximum, in most cases. So, most of those that "once were" are no more.