The figure is a late Republican Roman centurion, one of the plastic set from Warlord Games. They're excellent models, and extremely cheap too, compared with metal 28mm figures — these ones work out to about $1.33 each, which would actually make a whole 28mm wargames army feasible. They do a range of waterslide transfers for the shield designs too, which would make recreating them well much, much easier, though as of writing they're mostly out of stock.
My knowledge of Roman arms is fairly sketchy, so I don't know just how accurate this paint-job is. It will do for me though.