I acquired some spare parts for my MD-7 including all three transformers.

Two of the three checked out according to the manual. The tone oscillator transformer T-57 may have an issue.

The manual says the resistance between pins 1 and 2 (case) should be between 58-75 ohms.

I measure 5 ohms.

I measure the inductance between pins 2 and 4 to be 0.28H, and that's within the range specified in the manual.

I'm wondering if the spec for the resistance between pins 1 and 2 is wrong in my manual?

My manual is AN 16-30ARC5-2 15 Dec 1954

If you have a different version of the manual, can you please check the specs for T-57?
The info is in Table 7.2 in my version of the manual.

The manual gives no other resistance measurements for the primary. I measure:
1-2: 5 ohms
2-3: 30 ohms
3-4: 34 ohms.

Even if the 5 ohms is a bad value, this should not impact the operation of the Tone Oscillator.

I might be able to just add a series resistance between pin 1 and the connected switch.

73 Mark K3MSB