The way I remember them, with front skirts around the buffers, grill cover still in place and headcodes in use. I didn't spend too much time watching them storm through Reading on Cartics though.
David J. Hayes says "The May 1974-May 1975 Mandatory WTT shows 4E32 as an Air-Braked Company train from Severn Tunnel Junction (STJ) to Ripple Lane, with departure times from STJ at 01:50 MO (shown as empties), 12:33 TThSO and at 12:05 SO (until 28th September 1974). The upper deck of the "Cartic" looks devoid of cars".