I haven't gotten too much further in my experimentation with getting my Mac and Linux boxes to play nicely using nfs, but I did discover one more thing. As far as I can tell, Mac OS 10.2.8 does NOT support file locking natively. When I try to turn on file locking using NFS Manager, the option is greyed out and it says that this version of the operating system does not support locking. Mac OS 10.3.2 DOES support locking.
As of now, I have 2 machines that are working together, and 2 that keep clobbering the ambient file.
Happy New Year to all!