Collections of Scottish Armory, mostly medieval.

Internal 

• Academy of Saint Gabriel report 2511, which discusses Lowland heraldic style and lists some 15th century Scottish arms.
• An Annotated Bibliography of Scottish Heraldic Materials, by Zenobia Naphtali and David of Moffat. Also available on the SCA website.
• The Heraldry Society of Scotland. Their website contains some material of use to medieval re-creators. Their magazine Double Tressure often contains articles useful to us. In particular, the 2001 edition contains Leslie A. Schweitzer and David Hunter of Montlaw, "Charge Use in Late Medieval Scots Heraldry" (#24, pp. 11-32). Warning: Much of the website works only in Internet Explorer, and I can't get some pages to display at all.