Suggest you provide more info on the sail you are considering....you may get more good info.
If it was me, I'd want to know the boat it was originally designed and made for. That Pearson 10M of yours is relatively heavy and relies on the genoa for a large share of it's power. How close is the foretriangle and weight of the boat it was altready designed for? The weight question and where in the race inventory this sail was supposed to be used will tell a great deal about how good the fit for you may be. As an example, if the sail was originally made as a light air sail for an ultralight race boat, the cloth choices might not be as durable as a race sail made for your boat.
I'd also want to know the loft and if the sail is paneled or molded and what cloth types and weights were used. Pretty easy to change dimensions on a paneled sail...not at all easy to do so on a molded one.
It may turn out that it will be a great deal and fit but you should consider finding out some more to get a better idea.