It so nice when a new member answers the Welcome Mat. I think so many of us forget to look back to see if someone actual answers back. . I am probably the oldest collector on the forum that still collects . First Harbour Light lighthouse in 1996, a HL 177/417 Alcatraz. and still collecting purchasing over 50 lighthouse last year. Do you remember your mothers AOL user name or her forum name?

When your mother went to San Diego that would have been the first Harbour light reunion in 1997 which she would have received the New Point Loma HL604 and NPL mini HL605 reunion pieces.
I assume when you say standard lighthouse you mean the Limited Edition ones . Look for hand written low numbers, brown boxes, white box with words Castle studios and AP on the lighthouses, also check when manufacture, those made in 2008 to 2011 are in demand. Also Fresnel lens are going for $ 250 and up depending on the model.. Best thing you can do is a spread sheet with the HL name, number and the hand written production number. This will help you when you go to sell..

Good luck