appending more recorded bits to an existing and previous named macro

[David R]

if I do M-x define-keyboard-macro
I can record a macro.
If I do start-keyboard-macro I can add a bit to the last macro defined.
Wouldn't it be a good idea to create a function which will collect a 
named kbd macro and put it in the allocation as the last keyboard macro 
so that if a person decides at a later time to append an extra recording 
by a macro which is older than the most recently defined macro, he can 
do so.?

David R