[surfamtn]

Hello gang,
So I need some help with my 1966 305E four speed.
I was driving around town yesterday, truck was running great and it was a beautiful day, as I took off from a stop light and shifting from second to third the clutch suddenly stopped working. it took me a minute to figure out what was happening, at first I thought I wasn't pushing the clutch all the way to the floor, then I thought it was just missing the gear with a stick. Eventually realized that pushing the clutch pedal wasn't doing anything to the clutch itself. Engine running running fine, I was able to coax (slam) it into gear and continue driving but at the next gear change I was unable to shift normally still.
The pedal still goes all the way to the floor, it does feel like there is a little less resistance than typically. Previous to this one specific shifting event I had been driving around town all day with no problems, no difficult shifts, no slipping or loss of power.
It's been raining cats and dogs here over the last 2 days and I haven't been able to get under the truck to look and see if there is some count of linkage broken or anything. I was wondering if this is something that sounds obvious to anybody in the club, or something with somebody's experienced before.
I consider myself a very green and self taught mechanic, I'm pretty sure this is a mechanical clutch without hydraulic assist right?
It seems like something suddenly became disconnected or failed, it doesn't really feel to me like I suddenly wore through the entire clutch plate.

Ideas?