Well most transceivers can be easily converted from 440-450MHz to 430-44-MHz by cutting some diodes, this is one of those cases were it can not be done :-)
To change the RX/TX freq You will have to replace the two PLL crystals (X3 and X4)
Change X3 from 35.74417 to 34.912MHz
Change X4 from 33.9275 to 33.095 MHz
For the 1.6 MHz repeater shift remove diodes D13 and D14
For the display to show 430-440 Add diodes D15 and D16 (1n4148/1ss53)
Adjusting the IC45 is easy, use the atlas toko to get the freq on 439.000 and then use the 5KHz shift knob and adjust the freq with the red c58 trimmer to 439.005
Be careful with the toko, the core can easily break !
If You have a good signal generator it might be a good idea to align the rx although in most cases it is not necessary
Unfortunately I had no service doc of this rig.