Start by researching this site:http://www.camaros.org/geninfo.shtml
--especially 9. Spources and 10. Historyhttp://www.camaros.org/options.shtml#RPOSpreadsheet
Without the cowl tag it is an uphill battle. 81 may seem like a long time ago for you, but I can assure you there were great looking clones in the 70s. You need to find what other numbers you can. Start with [from General Info. sources] Alan L. Colvin's Chevrolet By The Numbers, The Essential Chevrolet Parts Reference, 1965-69, Robert Bentley, Inc., 1994. ISBN 0-876-0956-9. Post what you find in Decoding.
In any case, you have the potential there for a great car. Good luck and post what you find.
BTW, take a look at Ed,s post about sources in this thread: http://www.camaros.org/forum/index.php?topic=40.msg250#msg250