Play likely does not indicate the need for new bearings. The spindle nuts may not be tightened properly. They were probably that way when you towed it last, since I can't imagine how they would loosen. We're it me, I'd pull the bearings and repack if they look good, otherwise not scarred or rusted or damaged to the eye.
If you really really want new bearings just because, the easiest way is to pull the bearings and look the numbers up along with the races and the seals.
2006 Sunline T-1950
2019 Ford F-250