Originally commissioned by Neville Swales of Building The Legend Limited,[1] the LM69 was developed as a homage to the 1966 Jaguar XJ13 race car which was intended to participate to the 24 Hours of Le Mans.

[3][4] The LM69 was never intended to be an exact replica of the XJ13;[3] rather, Ecurie Ecosse tried to imagine what the XJ13 might have looked like if Jaguar continued its development until 1969.

This explains the marked retro design, as well as the absence of post-1960s technology: the LM69 would have complied with any 1969 Le Mans regulation, thus virtually allowing Scottish racing team Ecurie Ecosse to participate to the 1969 event (hence its name) and racing in the same league of the Ford GT40 and Porsche 917.

[7] It is based on the same design of the original Jaguar power unit, and comes with either 6.1 L, or its stroked version developed by Neville Swales with capacity expanded to 6.8 L. Distribution and injection are standard for the period; modern, electronic optional for the latter would be available.

By comparison, the original 5.0 L V12 engine of the XJ13 had an output of 502 hp (374 kW) which could bring the Jaguar up to 170 mph (274 km/h) in fifth gear.