Alembic F-2B
Well, since no one else has jumped in, I'll break the bad news on this one. Alembic doesn't have serial number records for electronics (F2B, F1X, SF2, etc.), just instruments. Age on F2Bs can be approximated in some cases by cosmetics--case color, knobs, city on ID plate. If you post photos Mica might be able to come up with a hypothesis.....
Kent's right - we only track the instruments. Tell me the city printed on the back and a description including the chassis color and knob color, and we can get you an approximate age.
I pulled the file for 4318 - which is a 1987 Spoiler, but that wont help much
As far as age, this has the teal/black casing with the aluminum knobs mentioned in the FAQ, and Santa Rosa, CA is the city on the back.
The auction with photos is here:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=7356171627 (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=7356171627)
These are probably from a short period in the mid eighties.