[Mondial]

Cab you post a picture of the tuning slug from the replacement osc coil? Unless the slug is made of some unknown unusual material, it seems impossible that moving it in and out of the winding would have no effect on the osc frequency.

If the slug is made of ferrite or powdered iron, it will lower the resonant frequency of the coil when inserted. If made of aluminum, copper or brass it will raise the freq.

Since your osc appears to be too low for the received freq, try removing the slug and insert a small brass or aluminum rod or screw into the coil and see if it acts to reduce the error in receive freq vs the dial setting.