My dad served in active war time. They currently still live independently. Because my mom brings in too much from her pension, my dad can’t qualify for assistance. So they don't make enough to live in a decent assisted living, but make too much for supplemental assistance. My dad needs to go to a full care facility. How in the world can I get him into somewhere decent? If they sell theire mobile home, will that allow him to qualify for help?
As Jeanne says, you need expert advice in order to get your parents the help they need.
Rules are very different for married couples than for single folks. Your parents need to talk to experts about their particular situation. Call their Area Agency for Aging and see if they can refer you to someone to help.
Selling the mobile home won't help. In fact, don't make any long-term changes without talking to an expert.