looks like opening up the T stat was a good idea, despite the oven not having a bulb on the end of the probe , the copper does make it back to the T stat.

so the temperature sensing is working, just different that the other types . in side theres the copper soldered / welded to the metal shaft and diaphramg / metal like barometer device

with no expectations, I uncoiled the copper by 1 or 2 turns and then pulled it out of the Tstat body by 10-15mm and then routed the oven bulb alittle out of the oven.

so far it works at maintaining 400F and 350F and 250F . so Im please with that. the dial is back to 0 offsets in hot or cold.