In case anyone has been wondering what had happened to these rules since PSC sold out of the Compendium edition, they are available as PDF downloads from CCC games, along with the game accessories that are also usable for
Renatio et Gloriam, and in printed form from Lulu. (Pacto is now one book and Maximus and Magna a separate volume). I learned this from Simon Hall via the ReG forum and didn’t want the information to go to waste.
https://ccc-games.co.uk/product-category/mortem-et-gloriam/