The Supp. Regs do say Classic Dirt Track rules for Tyres, KTM47,
"26. TYRES
All machines entered must comply with the current GCRs for Classic Dirt Track competition (section 16).
And they say, "16.15.5 Tyres
16.15.5.1 Tyres must comply with the following:
a) Metal studs, spikes, chain, rope or
other non-skid attachments may
not be used unless permitted by the
relevant Supplementary Regulations.
b) Paddle or scoop treaded tyres may
not be fitted."
So, as you say, either rules say the same !
Foss