Well what I suppose they'll do is, continue replacing all the guard E-models with active duty R-models and continue upgrading them until the damn wings fall start falling off (Blk40.x, Blk50, Blk60, etc...). They probably figure that since the guard won't use them as much anyway, they'll be able to salvage 10-20 more years out of them while they slowly replace the active duty -135's with KC-45's.