I’m ok with 8mm wheels and tires if they look right. Not so keen on brass chassis unless the car is a resin body with a thin brass chassis like Penelope Pitlane. Please include independent rotating fron wheels because my Scalextric Austin Mini Cooper comes that way. There is not room up front for an axle where the guide is up front. Actually I don’t mind letting independent rotating front wheels on any car. (A famous 917 cheat I purchased has secret independent front wheel.) I like those cars you found and included.