[TenTec] Omni D - which type?

[Werner 'Joe' Jochem DK7VW]

Two days ago I purchased an Omni D - S/N 546-2280. Since the vendor didn't
provide an Owner's Manual I tried to find one via internet.
On www.qsl.net/tentec I found the different types of Omni D (546, 546B,
546C) and downloaded the manual for the 546 (the only one available there).
Looking at the pictures showing the front panels of the different Omni types
and the downloaded manual I have to confess: I am confused. My Omni doesn't
match to any of the shown types, ups ...

1. The selectivity is chosen by a rotary switch with four positions: CW-1,
CW-2, CW-3, SB.
2. There's no notch filter, but a squelch knob (with on/off function)

Any idea which type of Omni D I purchased and where I can get the
appropriate owner's manual? Many thanks!

73 Joe DK7VW