I worked a long time as an A&P before flying. I wrenched at 91 and 121 operators, later worked at a long haul freight outfit turning wrenches then got on as a PFE. Got furloughed, worked for a 135 wrenching and flying went back later in the right seat of a 727. Now work at a legacy and am in a pretty good spot.
Its possible, but takes perseverance and patience to pay off. Making good friends along the way can also help a lot.