Lots of discussion over tire choices for the Rialta.
I have a 2004QD and put the 195 front and 215 rear. All Nokian ( I'm in Canada )
Some have gone the 205 all the way around and a few have gone 215's.
Be careful about the spare as the carrier is not deep enough for the larger widths and not recommended to run different size tires on the front as it could ruin the transmission.
There is more discussion here: https://groups.io/g/Rialta-Tech/wiki/Tires
and also info here: Tires & Wheels