Another vote for Zokes while they were still owned by Marzocchi. I had some slightly later ones that did not have the canti stop (might be a optional arch). I will try and dig some pics out
Don't think it's a Zokes as i have an early one for sale on here and it is more rounded on the brace. Zokes also tended to have a rocker for the cables and not canti stop in centre. I'm thinking it could be shockworks or something similar.