Not Antonio DeMarco but Paddy Demarco. Who you got? Carter I version of Paddy and the Valero we saw in his title fights. 15 rounds if it matters to you.
There's very little footage of DeMarco (at least, available online). And, the Carter who DeMarco beat to win the Championship (and who would return the favor to DeMarco that same year of '54) was, as far as I can tell, known to be mob connected, with a few 'unreliable' results on his record. Nonetheless, based on his record, DeMarco was a top performer during the early 50s - fading out of contention soon after the Carter loss in their return and probably suffering from there not being a recognized 140 division during the period. But, in '54, he'd be a considerable test for any lightweight. If Valero was to go for a Championship during the '50s, then DeMarco's short reign might be the best time for him to take a shot (other than a go at Bud Smith in '55, maybe?). That said, if I'm betting on it and, using the available evidence, DeMarco would be my back here - for a Decision win.
