d2 antenna extension unit restoration

I won this relic lot in very low price, its translation as: 'Antenna part extension Specially accessories radio station Fu.A1 Torn.d.2 Wehrmacht'.

Didn't know it could be restore or not, but when compared with my d2 antenna, found it hope to loosen it from the base, as the bracket is made of copper and the shaft is iron.

After studied the photos and compared with my antenna base, found its really the parts of the d2 antenna extension unit.

Dropped it into vinegar for 24 hours, then in WD40 for a day, still can't turn a bit, but knocked it off the base.

The only solution left was by heat, tried to heat it at the stove, and it turned a bit, repeated couple of times, its finally released.