Thanks Ted
Seaboard Air Line had quite a few covered hoppers. According to Paul Faulk's SAL Color Guide book, Seaboard had the following:
77-ton Airslide (7100-7129) - General American
70-ton 2-bay (7600-7999) - PS (8 36" square hatches)
70-ton 2-bay (8650-8849) - ACF (29/-3" with 8 36" square hatches)
70-ton 2-bay (30000-30549) - ACF (35'-9" with 8 36" square hatches)
70-ton PS2 (30550-30749) PS (4 hoppers, 2 compartments 8 30" round hatches)
70-ton (58675-59474) PS (4 hoppers, 1 compartment, 8 square? hatches)
I haven't been able to find any ready-to-roll SAL hoppers, so I either had to repaint/letter a Weaver PS2 hopper:
I've requested Weaver to consider making these, but so far I've seen no offerings. It would be a very easy model to do Weaver