According to "Original MGA" by Anders Ditlev Clausager, some early production MGA may have been supplied with a type of jack different that any shown on this page. I do not have any information on that jack yet, and no picture.

This is the KING DICK screw jack supplied with MGA 1500/1600 cars. This model is commonly called the "bow tie" or "hour glass" jack because of the shape of the base. It has a three-piece handle similar to the one shown at far bottom of page. Place this jack under the front suspension or rear axle, and a two stage screw will lift the car several inches.

This is the SHELLEY model LJ225 screw jack supplied with late model MGA starting July 1960 and including the last eight months of 1600 production and all 1600-MK-II (click for larger picture). The handle for this one is a short piece of round steel bar 13" long to a 45 degree bend, then a further 1.5". It is turned by a ratchet mechanism operated by moving the handle back and forth.

Paint color for restoration is Duplicolor DE 1607 (Chevy engine orange).

This is a similar SHELLEY screw jack, model LJ225 59. Here the ratcht head is cast alloy rather than stamped steel. I am not sure if this one was ever supplied with the MGA, but I will make enquires.
 

This is a 6-inch SHELLEY screw jack. Handle is shown below. This model has a "bow tie" base similar to the King Dick jack, but with more rounded corners.

Period tool from a swap meet, not original equipment for any MGA.

This handle came with the black SHELLEY jack above.
Part number is 97H577 for the KING DICK three-piece jack handle.

This is another Shelley screw jack with rectangular base, application unknow but definitely not issued for MGA. Notice the single screw and peg height adjustment. (Photos supplied by Steve Gyles in the UK).