The title of this article is a bit deceptive, the automobile is in fact a 1955 BMW Leblond Speciale Berlinetta, though most of the front axle, and the entire rear axle of the Bugatti were used in it's build.

Some while ago I was contacted by the owner, if I could positively identify the Bugatti rear axle, and what did I know about the brakes fitted on the front??

Luckily, the rear axle was stamped number 553. As this number coincides with the engine number, my friend Kees Jansen could identify the rear axle as being from a late Type 57, in fact chassis 57772. That car had engine 553 with no compressor. It was one of the last to be completed in juni 1939. It was fitted with Berline coachwork and delivered to Bohny in Paris on september 11, 1939. Nothing more is known about the car, but obviously it was taken to parts before 1955, for the rear axle and front brakes to be used in the Leblond.

The Leblond was auctioned by Bonhams in their Les Grandes Marques à Monaco auction on May 15, 2004, and fetched € 43,700 inc. premium.
The below description is from the Bonhams website:

1955 BMW Leblond Speciale Berlinetta
Coachwork by Eugène Martin
Chassis no. 004

In the early 1950s, Talbot-Lago entrusted designer Eugène Martin with the task of designing the body for one of its proposed new models. Unfortunately, this was not a prosperous time for the French prestige car manufacturer, which was enduring a highly unfavourable taxation policy and uncertain finances, factors that led to this particular project being abandoned. Martin's promising new design might have disappeared into oblivion had it not been for the arrival of a new backer, Albert Leblond. The latter was no newcomer to the business; previously with Bugatti, he had built a BMW-based barchetta that distinguished itself in the Paris 12 Hours Race in 1948. As a result of this successful experiment, Leblond again chose BMW power in the form of the 2.0-litre six-cylinder overhead valve engine as used in the pre-war 326 model. Tuned to produce around 80bhp, this was installed in a Ferrari-esque, oval-tube, short-wheelbase chassis equipped with Bugatti brakes and Type 57 SC rear axle (Which we now know to be wrong), around which was wrapped Martin's graceful, aerodynamically efficient, berlinetta coachwork. The accompanying French Carte Grise indicates 1939 as the year of the engine's manufacture and 1955 for the completed car.

Presented in very good conditions, the vehicle is to original specification. The engine, rebuilt at the end of 2003 by the renowned Cointreau workshops, will require careful running in before its full potential can safely be exploited by a new owner. This vehicle was the subject of a six-page article in Le Fanatique de l'Automobile (issue 145) and was honoured in the "Authentiques" category of the 2002 Louis Vuitton Classic Concours d'Elegance in Paris. It has also taken part in many historic motor sport events, including the Grand Prix of Tunisia in 2002.

An intriguing fusion of pre-war mechanical components and post-war style, this handsome Berlinetta dates from a period when the scarcity of readily available competition cars led to the creation of numerous interesting 'specials' and as such represents a worthy addition to any historic motor sporting event. Currently in the hands of its third owner (the first, Albert Leblond, kept it from 1955 until 1998), it is offered with valid roadworthiness certificate, history file and sundry articles.

The Leblond as it is now
The owner sent me a whole series of photographs, above photographs showing the car as it is now. But also many photographs of the rear axle obviously, but also of the front suspension. An independent suspension which makes use of the Bugatti stub axle and king pin. The photographs below is to show how one can modernize a Bugatti suspension.