Hi Glen,
Generally speaking, Goodmans were usually rated to between 20 and 30 watts max (at least the ones I've seen). I've got a pair of 15s and I have to say there is very little xmax. Though they sound quite good in a vented enclosure, I'm not sure how they would do in an OB situation. I'd be afraid you'd have them barking pretty hard if you put too much power to them. I've never measured the TS params on mine either so they may or may not be a good fit for an OB.
Ever considered an Altec 416? I've heard an OB using one and it was fairly decent, limited but decent.