I was one of a group of 8 actors who did the first animatic voice recordings in the pre-production of the scirpts in 1999. Later, when I was doubling as the aged Theoden (for which I had auditioned but didn't get!) when I was asked to be the Rohan Soldier in The Two Towers.
In Return of the King I was actually doing a lot of reading off lines, which involved working very closely with the main actors as they did their pick ups.
I was thrilled to be asked to be Grimbold, and also actually played another part who had a line straight after Grimbold's in the film, but it has been cut... maybe it will turn up in the special edition."