Welp, just spent the morning talking with USAA and affiliates. To sum it up, nobody is covering a skoolie unless the conversion is pro done "to comply with RV codes. When I called back and said private bus (huh?) and got transferred to commercial side I made headway. Since the bus is for "hauling people and equipment to camping locations" and NOT a conversion I was offered a progressive policy via usaa for about $650/yr. May try calling GMAC tomorrow.