Hello,
No, you will not be able to upgrade RUT9 router with 01.497 to any firmware, newer than 01.999. Early "02.xxx" firmware versions already require bootloader's upgrade.
There is no reason for you to downgrade router from 03.832 to 01.497 firmware, since this would not provide any relevant information for you. I.e. This lab router with 03.832 already uses newer bootloader version than the ones in the fields, therefore upgrade process would be seamless. However, performing same actions on your field router would brick them. Trying to upgrade bootloader of the router, which is already "bricked", might damage the router irreversibly.
The correct procedure in this is case is to upgrade router's bootloader first and only then its firmware. If you want to "test/check" the procedure, this should be done with one of your device, which is still using 01.497 firmware (and therefore - older bootloader version)