I can answer my own question, at least in part. In the t/httpd.conf location /TestAPI__access has AuthType none and AuthName modperl defined. If I comment those out t/api/access.t passes except for test 7. Test 7 expects 'none' as AuthType whereas in fact it is 'undef' now.
I've looked through the server 1.3,2.0, 2.2 & dev documentation. They all say that there are 2 possible values for AuthType - Basic or Digest. From my apache/mp novice perspective it looks as though access.t really should also fail for mp vs 2.2.6 since 'none' does not appear to a legal AuthType. Anyway - should access.t & t/conf/httpd.conf in the mod_perl trunk be changed? I am quite happy to do this. Thanks, Rolf