You could try calling PT Engine up this way. They deal almost exclusively with Volvo. 207-324-1019. Try to ask for Phil JR. Phil SR will keep you on the phone forever.
I had the 122p, same block as the d12. Had great luck with that engine and everything was very easy to work on. A friend of mine runs a d12 and loves it, puts 500plus ours a year on it.