Turns out that Spartan no longer stocks these "low volume" parts and has sold them off to Vintage Parts. P/N is RW7719-2924G BUT is specific to the rear axle type. So call Spartan first with your VIN info to verify.
Kit includes 2 hub covers, mounting kit, center threaded emblem and special tool for tightening & removal. Less than $200 with shipping.
Another expensive RV lesson....