Batboard

how does one know when they are dealing with a toolproofed MTS2000?

That is, is there a serial number series, a date of manufacture to reference, information on the radio's tag... or does toolproofing arrive with a certain release of the RSS ?

Toolproofed or toolproof-able? Two different things.

If the radio has been toolproofed, it will display FAIL 01/93.
If the radio CAN be toolproofed, it will have firmware revision R05.42 or greater. You can view this by reading the radio or by placing in self-test mode (IIRC). The radio may have shipped after 2/27/95 (implementation date of toolproofing), but this isn't a guarantee - a pre-95 radio may have been FlashPORTed in the field or upgraded by the depot during a service visit.