No, not all aircomms are p25 conventional but there is p25 digital conventional aeronautic use, the area that I know would be USFS and DOI fire service. I live by the water and also the US Coast Guard uses p25 digital conventional VHF and UHF regularly, big advantage is it can be encrypted arbitrarily when needed.
I can understand not needing P2 secondary to encryption, my entire region is P2 encrypted but police only, fire is only part-time encryption and rarely used so the P2 comes in handy.
I picked up four of those 197's when RatShack went belly up under $200 a piece. Never opened the boxes, just waited for Whistler to jack up the price of what was an obsolete radio then and turned them around at a nice profit.
Love your pro 2004, I remember getting one when they first came out, terrific modifications that are irrelevant now unless I guess, you wanted to speed up your scanning. That series from GRE were terrific radios in pre trunking days.👍