I think the wheels pretty much depend on which Austin Seven racer you are talking about and just how fussy you are. There is no easy way out.
Mr Jamiesons twin cams are easy in one respect in that the brakes fill the wheels, though the wheels themselves are rather special.
All the rest have rather smaller brakes and a variety of wheels, most with a mere 36 (?) spokes, all that is really needed on such a light car.
The wheel in the picture is my 'test' wheel, built up using a home brewed wheel, off the shelf etches and home brew wheel nut, with the wheel pattern to suit no car in particular, having 48 spokes and with scale dimensions for a 16" wheel. You will note that the spokes are side laced whereas most wheels using etched spokes are centre laced.
I hope that when my own etches are delivered a tidier and more realistic wheel will be possible.
Alas none of these etches would actually be correct for an Austin unless that car had been fitted with rudge hubs, when of course, any wheel could be fitted.
If you wish to have a bash at your own wheels, I'll be happy to let you know the ins and outs of what I have done and why.