Date: 4/27/2008 7:21 pm EDT
I think journeyman is correct in saying the cutback (black tar)adhesive should be fine to go over. any home center will carry a cement based patching compound that could be used to skim over the old adhesive to encapulate it if needed.
The big thing were not addressing it old resilient flooring with cutback from the fifties most likely contains asbestoes and care should be taken when any removal is performed.codes vary by location, but most will allow homeowners to perform the work themselves without penalties.your local health and human service office should be able to give you advise on how to handle the removal or if its appropriate to have a professional to the work.
Avaire tile is a perfect product to go over old asbestoes products, and it will last for many many years. so protect your health and saftey so you can enjoy your new floor for many many years.