Ok - time for an update, as I have eventually got around to fitting the new Toyo tyres on Eugene...
(Thanks to Uncle Albert!)
As mentioned earlier I went for Toyo Proxes R888R
2x 185/60r13 for the front - 2x 205/60r13 for the rear - both on the same 6" rims.
I've only done 40 or so miles so far, but I have to say they are very, very impressive.
I know the 021Rs were old, so a fresh set of just about any rubber would feel good, but these feel just amazing so far.
Nicely compliant, and not at all harsh compared to the 021Rs, but very, very grippy in the warm weather we have today.
Inflated to 18psi all round as a starting point.
And they look great too - the 205/60r13s in the rear do not at all look 'balloony'.
And the ground clearance is not at all too compromised - 80mm to the lowest point of the sump with the lower wishbones (rear arm) parallel to the ground.
This is looking to be a good choice!