Yes, you might want to backup. The gameplayobjects.con is in server.zip\gamemodes\gmp_coop for COOP and SP3 for singleplayer. It changes vehicles from mostly Italain back to German, as set by AJ51. The init.con switches armies from Aussie and Italian to Brit and German. It does have an outdated gameplayobjects.con though. I'd recommend playing it as it was without the replacement ie. Aussie versus Italian.
If you must restore, go to the server.zip\gamemodes\gmp_coop and init.con in the daylight tobruk map and use those instead, as those are up to date. The map might be ctding during gameplay because of the flare gun. I will make a new init.con to get rid of the flare gun