Good news is that 205/65 R15 tyres give a similar circumference, just 1.2% larger than your 185's. Note ZV7 has replaced ZV5 and factory fit on current cars.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone