[Heathkit] SB-610 40-747 med. freq. coil?

[George KB2Z]

Hi all,
I am looking for an SB-610 coil, or replacement part info. Would anyone 
know of a source for a 40-747 medium frequency coil? I want to set the 
vertical input for a 1650kc rx i.f. I have a 40-748 (3 to 6Meg) installed 
in the unit that I would be more than happy to trade. Any input or 
suggestions welcomed.
Thanks in advance, George KB2Z