I've created my own rules for making the old RM2 professions in RMU, and have converted some of the old character classes. The latest version of my skill costs are here (on post #26 of this thread):
http://www.ironcrown.com/ICEforums/index.php?topic=17454.0
I also outline why I think RMU will not be able to recreate all the old classes unless it adopts some rules for giving individual skill costs (the short answer is: unless you have individual skill costs, you really can't recreate all the old classes because you can't give fine enough distinctions in the skill costs; you just end up creating more No Profession classes). So my rule is an optional houserule that allows you to recreate the old classes with individual skill costs.
I also have a Guild Companion article on this, but the most up-to-date version of the skill-cost list (with Archmage, Astrologer, Beastmaster, Nightblade, and Warrior Mage) is on that thread above.
I do plan to do more of the old RM2 classes, and ideally all of them one day, precisely for people like you and me, Mark.