Yes, AS1313 is rare. It definitely corresponds with Z2541, and it looks like it belongs to the branch of Z2541 labelled S2268. Further on the S2268 branch, there is an SNP labelled A6550, and this seems to be a match for AS1313. I'm the administrator for an uncle's kit at FTDNA, and it has tested positive for Z2541. I also previously ran the kit's STR markers through Jim Cullen's haplogroup predictor and it came up with a result of 91% for AS1313. Have you done any testing for Z2541?