I haven't dealt with them personally, yet. However, I did talk with the owner on the telephone and he told me the best way to get an exact replacement was to ship the old rudder to them and they wouldn't have a problem duplicating it. He did say, however, that despite the measurements made by owners and manufactures specs, most rudders have some tiny differences that can make a huge difference in the fit. My rudder is on borrowed time, I've repaired it twice, the next step will be replacement. I'm too old to make a new one myself, so I guess I'll have to rely on them to provide me with a good replacement. The folks at the boatyard across the river from my marina highly recommended Foss and said they're never had a problem with the rudders they've received. They did say, however, that they always remove the old rudder and send it to them to be replicated.
Keeping my fingers crossed on this one,