The small buff coloured card is a compass correction card for Spitfire P8640 the following website has this to say about the machine:

The following is what the RAF Museum sent about the plane:
“Probably named after the village of Aberford, West Yorkshire, Mk. Vb P8640 was taken on charge at No.6 MU Brize Norton on 2 June 1941 and delivered on the 26th to No.609 (West Riding) Sqn at Biggin Hill, engaged on sweeps and bomber escort operations. These duties continued with its transfer on 6 September to No.92 (East India) Sqn, also at Biggin Hill, until being sent to No.610 (County of Chester) Sqn at Leconfield on 15 November for convoy patrols.

On 26 March 1942 Plt Off S. Lanunski P0419 (Polish) of No.1 Delivery Flight collided with a stationary lorry on the arrow perimeter track at Kidlington, being unable to zig-zag in the usual manner in order to see ahead. Although the damage was only classed as Category A, it was flown to No.1 Civilian Repair Unit later the same day for repairs, returning to No.6 MU Brize Norton on 1 June to be despatched on the 20th to High Ercall.

On 12 September it was allocated to No.308 (Polish) Sqn at Heston, but as this unit was away at armament practice camp, it joined No.302 (Polish) Sqn also at Heston, coded WX-G, engaged on sweeps and bomber escort duties. On 8 November P8640 was Category B damaged while being flown by Flg Off E. Horbaczewski P0273 when it was struck by the propeller of W3702 (WX-A Category A, Plt Off M. Muszynski P2011) while returning from Circus 235. Both aircraft returned safely to Heston where W3702 was repaired on site and P8640 sent on the 17th to Air Service Training for repair, awaited collection on 8 February 1943 then delivered to No.15 MU at Wroughton on the 20th.

On 13 May it was sent to Vickers for fuel system modifications, being delivered to No.33 MU Lyneham on 21 June, then returned two days later to No.15 MU Wroughton, being issued on 7 July to No.416 (RCAF) Sqn at Digby for Ramrod and Rodeo operations. It was taken to No.3501 Servicing Unit at Cranfield on 15 July, returning to No.416 Sqn three days later only to be involved in a minor accident on the 20th and repaired on site. It had joined No.2 Tactical Exercise Unit at Grangemouth by 9 November, when the engine failed and a forced landing was made, Category B damage being repaired at a civilian repair unit. It is next recorded with No.186 Sqn at Tain on 10 February 1944. This unit was renumbered No.130 (Punjab) Sqn at Lympne on 3 April and began operating bomber escort duties and also patrols.

On return from a patrol on 28 April Flt Sgt C.H.T. Clay swung on landing to avoid an overshoot and hit a floodlight post, Category Ac damage being repaired on site by 23 May. P8640 was then sent to Scottish Aviation at Prestwick on 8 June, to be waiting for collection on 15 July and delivered to No.8 MU Little Rissington on the 25th. The aircraft was despatched on 2 May 1945 to No.6 MU Brize Norton, from where it joined No.1 Air Gunnery School at Pembrey two days later. On 15 June it was relegated to No.33 MU Lyneham, being despatched on 4 September to Portsmouth Aviation to be struck off charge six days later.”

Information taken from:
http://www.parlington.co.uk/locations.lasso?process=9&subProcess=local6