Any infos about Dusty Hill's "studio rig" ?

Hi,
We know Dusty's live rig but there's not many infos on what he uses/used in the studio. According to this interview (made during the Mescalero era), "Dusty’s studio rig" is "an old Ampeg SVT head with an 8x10 cabinet". I haven't found more infos but I'm really curious about it.
ZZ Top: Liquor in the Front, Poker in the Rear | Guitar World