Almost certainly one of the Xicon IF transformers at Mouser will do the trick:
Part 42IF-10x for 455KHz units
Part 42IF-12x for 10.7MHz units
The trick ( as you already noticed ) is figuring out which primary / secondary impedance you want.
Most of them have high-ish ( 15K - 50K ) primary impedance, and either low ( 300 - 600 ohm ) or medium ( 4K -6K ) secondary impedance.
From the schematic, 10MHz transformers are connected primary to primary, so I think you will be good either way.
Two of the 455KHz units have the secondaries floating ( only using the primary for its inductance ), so I don't the secondary impedance matters.
The other two 455KHz units are feeding the (ancient) Harris 3088 receiver chip ( where did you find one of these? ). The data sheet for this seems to indicate that the input impedance is in the 2K range.
If I were to have a go at this, I'd try:
Xicon 42IF102-RC for the 455KHz units for its lower secondary impedance
Xicon 42IF123-RC for the 10.7MHz units for the lower turns ratio on the "back to back" connected T2 & T3
I think you could probably get any of them going.
Good luck.