Yes they are available from Dave Barton in the USA, his website is here
http://www.davebarton.com I have just replaced the Volvo badge in the centre of my steering wheel and the one from Dave Barton is, IMO, better than the original one.
This is what I ordered:
VOLVO Steering Wheel Insert.
Volvo Dome Blue-Chrome Type 1 - 35 x 8mm $7.00
Qty: 1 at $7.00 ................................................ $7.00
Shipping cost was another $6 but at $13 total cheaper than a new steering wheel centre. As far as I am aware they are not available in the UK....... unless someone knows differently.