Looks about right. I think the 9806 came before the 9833 though. There was always overlap between the Faraday and Federal Signal notification appliances, so they would’ve been in Simplex’s product line at roughly the same time.
I put the 9806 after the 9833 because I saw 9806s on 4904 plates as well as 9838s on 4904 plates (online of course) so I thought they would be closer than the 9806 and the 9833.
I think I remember seeing that Simplex sold the 2901-9806 from the late 70’s up to the mid-90’s when they stopped using Federal Signal products. Meanwhile, the 2901-9833 was discontinued and replaced by the 9838 around 1985 or so.