Having just started the restoration of my son's Mk3 I've been shopping around for the best deals in shielding gas and came across Ruses gas in Bodmin www.rusesgas.co.uk who appear to have very competitive rates.
I've just picked up a 30 litre Air Products cylinder (93% Ar, 5% CO2 & 2% O2) for £85 inclusive of VAT and with no rental/admin/collection fees.
They also do a 47 litre cylcinder at £110 all in.
HTH.
