I auto-x'ed on old cracked hockey puck tires for a season. Traction sucked but they held together. These will probably be fine, like OP said it's up to the buyer to make the call.
Woot! Guelph E30's!
p.s. Lino, I've passed your car for sale add around to a few people I know in Guelph because it's a decent deal. I haven't heard back from them yet though.