Bruce is correct…
A basic, but late Mk.1A; due to the countersunk holes for mounting instruments.
A bit of a bitza by the look of it.
The ASI is calibrated in Knots… Bomber Command converted to knots from April 1st, 1945, with the rest of the RAF following on April 12th. (Mechanism Ltd. Croydon operated from 1955 until taken over by Negretti & Zambra.)
There’s also something funny about the Rate of Climb. It looks to be a short body version; but the Static connection is in the wrong place; the adjusting knob is missing, and the 6A/942 blue printed code looks very post-war.
There is no rear pipework, anti-vibration brackets, mounts; or manifolds – which would cost as much to acquire as the opening bid of £440 if not more.
The auction house estimate of £750-£850 sounds about right for this item… a complete period panel with the correct instrumentation would cost at least twice that amount.