Wha...??? Two THOUSAND dollars?! That sounds like a 'I don't want the work' price...but, you have much more info.
Are the radiators designed for chippers unique to each manufacturer's chipper or do the same engine/radiators get built for other stationary engine applications? It seems...and I know I don't have all the info...that soldering a patch on a radiator tank isn't that challenging.
He works with Landmark Machinery, they rebuild chippers and have a good selection of parts available. Trevor is pretty good about responding on here when he is tagged, but you could contact his business directly with a Google search.
Have you tried searching for that particular size of radiator and omit the Vermeer details from your search? You might find one that fits with different mounting, a little welding or drilling could fix the mounting issue. Not 100% stock but a cheaper fix to get you running again