As we know by now, 472-479kHz it will be. In an earlier post I revealed some "cheap" frequencies which would mix into the new band.
Some further options using industrial crystals:
DigiKey sells a 4.754687MHz crystal... count to (divide by) 5 and further divide by two results in 475kHz. A super-VXO could be an option here.
The above mentioned count to 5 solution applies to the following crystals, found at the same source: 9.494531MHz, 9.509375MHz and 9.545MHz. Other crystals would allow for an out of band I/Q-SDR LO: 9.600MHz, 9.625MHz and 9.7941MHz. Here, the chain would be count to 5, divide by 4.
Further: 18.9375MHz, 19.0625MHz and 19.069928MHz and for I/Q-SDR: 18.869MHz, 18.8696MHz, 19.200MHz, 19.280MHz and 19.440MHz. Consequenctly, the chain would be count to 5, divide by 8.
Plus: 28.59375MHz, 28.5938MHz, 28.636MHz, 28.6363MHz and 28.63636MHz (count to 3, count to 5, divide by 4).
Taking it even higher: 38.000MHz and 38.00053MHz (count to 5, divide by 16). I/Q-SDR: 38.400MHz and 38.880MHz.
Also found at DigiKey: a 7.680MHz crystal. Divide by 16 results in 480kHz. Again, a super-VXO and some (severe) down pull should generate a signal in the band. This crystal provides easy access to I/Q-SDR: LO spot om 480kHz, even a mere 24kbps sample rate would cover the whole band. The same applies to the 15.360MHz found at the same store.
All the above mentioned crystals are of industrial kind. One option would be order one for the favorit solution, the other option would be to carefully watch out for those frequencies before dumping old computers & Co.