Sir Brian. . . . . .

Don't have any schematic for that 88A unit but your numbers reflect the station error being about the same at both ends of the BCB.

(Initially we are considering that your dial scale pointer is centered in its extreme adjustments . . . therefore not being just a mechanical alignment error ?)

That would then suggest of the oscillator trimmer being set with too low of a capacitance setting.(Under compressed)

Hopefully, that trimmer is built into the main tuning condensers framework, as most units are.

Try tuning in the lower frequency station and tune off from it just to its lower frequency side and then very slightly tighten down on the oscillator trimmer capacitor a wee bit.

That should result in the lowering of the local oscillator frequency.

Also, that should then result in the radio coming right into tune onto that station again .

Then you just incrementally down tune and adjust the trimmer as you " walk " the stations tuning down to its proper position.

When the oscillator trimmer is set properly, then tune to the higher mentioned station or one closer to 1400-1500 kHZ and use the companion antenna trimmer to get the best reception of that station.

If your radio is COMPLETELY different than the above construction and design . . clue me in with its schematic . . . to consult against.

73's de Edd