Sorry, I am just relying on his photos too. I guess that's one good question to answer - when was the S-1 introduced Also what is a delta tone control?

Delta-Tone

Some Fender guitars have a unique tone circuit that features a “Delta Tone” Control. The “Delta Tone” system consists of a high output bridge pickup and special “no-load” tone control for the middle and bridge pickups. This new pot has a detent at the 10 position which bypasses completely any filtration through the capacitors. Unlike the TBX, which had a detent at the 5 position and gradually reduced the amount of filtration through the capacitor, the Delta-Tone’s “no-load” feature eliminates filtration completely at the detent and the result is more of the direct presence of the pickup.

Would that not be a Delta Tone control?

"I'm not a guitarist so I really am not sure. However when I checked the guitar it looks like the switching is on the bottom tone control knob as it somehow has an on off click on it."

Correct me if i am wrong here, but was the Delta tone Control a push/pull. i thought it activated when the tone control was set to 10, and just basically bypassed the tone control, letting the unfiltered signal through?

the TBX, like mine had a detente in the lower tone control, at the '5'. they replaced this with the delta tone, but I don't think it had a push/pull pot.

I would guess someone just installed a standard push/pull in that tone control, and used it for a coil tap. very common mod on Hb equipped guitars.

The Delta Tone works on the bridge and mid pickups. When the pot reaches 10 it clicks and removes the tone control from the circut and makes the pickups wide open with treble (no Load)

My 97' American standard Strat,
has a detent in the bridge/middle pickup tone control as described above, in the 10 position. However, the specs of this guitar sent to me from fender consumer relations, state that the delta tone control wasn't installed in such strats until late 99'. Any help here will be much appreciated. Thanks!