Welcome to the Forum.
As I recall, the Irish made Gold series, of which the S101 is part, were given a serial that started A00, followed by a three digit number. I would expect that it is A00145.
I found this thread which talks about a S101 A100145 and gives a date of 2002. I suspect that it is a near relative of yours. (See Steve's comments). It should have really opened up by now.viewtopic.php?f=3&t=1077&hilit=s101
I hope this helps and that you enjoy being an Avalon owner.
I have two Avalons, including the Jacques Stotzem Signature which was part of the Gold range and is a lovely guitar.