Mercedes E230 Class Estate 1990 - Drop Rear Seat Problem - GRUMP

The catch on the O/S rear seat will not release preventing me from dropping the entire rear seat. The N/S catch releases but the bar carrying the luggage cover and dog guard prevents both seats from dropping. The release lever on the top of the O/S seat would indicate that the latch may be only partly engaged but the seat back will not move at all and the lever appears to have no effect.

There is no evident way of getting at the catch but, if I could remove the bar carrying the lugage cover I might stand a chance of releasing the seat. Any ideas?

Grump