A couple of thoughts:
First, I believe that there is some mechanism in IEEE 802 address for
locally defined addresses. Hams, if they wanted, could define such
a block and develop a method for allocating addresses.
Second, one should think about the use of an name to uniquely identify
a station (e.g., a call sign) versus the use of a name to locate a
station. In many cases, it makes sense for the name used to locate
a station to have some topological significance. IP addresses, for
example, are generally assigned so that they have some topological
signicance, such as all IP addresses in a geographic area (for hams)
have the same prefix.
Personally, I think using ham calls in the AX.25 link/network layer
protocol has set amateur radio networking back a number of years.
Because calls are assigned without any topological significance,
they don't support any reasonable routing solution other than
having a master list of all calls (perhaps within an area) and
where each call is located.
-tjs