Philosophy
ABSOLUTE PERFECTION COMBINED WITH TRADITIONAL CRAFTSMANSHIP
Since 1984, HK-ENGINEERING has been the first company in the world to specialize in the restoration, maintenance and sale of Mercedes-Benz 300 SL vehicles. More than 35 years later, the HK philosophy of “passion, perfection and tradition” is still the cornerstone of all business activities relating to the 300 SL and the trade in premium classics.
The HK philosophy stands for the highest quality standards in the restoration and simultaneous preservation of as much of the original vehicle as possible. The Pollinger team of experts gives the historic vehicles a new shine with attention to detail and the greatest possible use of original vehicle parts.
THE BEGINNING OF A PASSION
The experience that Hans Kleissl gained while restoring his own 300 SL Roadster in 1979 gave rise to the idea of setting up a restoration business that would focus exclusively on this type of vehicle. Only through specialization and the ever-growing wealth of experience that goes with it can the highest possible quality standard in vehicle restoration be achieved. At the time, Hans Kleissl was the first on the scene to implement the idea of concentrating on one type of vehicle by setting up HK-ENGINEERING.

EXCLUSIVITY AND PERFECTION IN PURCHASING, RESTORATION AND SERVICE
HK-ENGINEERING’s service promise includes the greatest possible use and preparation of original parts in the Pollinger Manufaktur – from the restoration of old leather seats to the touch-up of old paintwork.
UNIQUE FOR OVER 35 YEARS
HK-ENGINEERING has focused on preserving old original vehicles for over three decades. As a result, the company is not only regarded worldwide as a pioneer and trailblazer in the industry, but also as the epitome of outstanding expertise in all aspects of the 300 SL. Over the years, this expertise has been gradually transferred to other classic automobiles.
Portrait
AWARDS AS A RESTORER
For over three decades, Hans Kleissl has dedicated himself to the preservation of historical cultural assets, be it in the automotive sector around the Mercedes-Benz 300 SL or in the reconstruction and restoration of historical buildings such as the Polling monastery estate with the old brickworks or Arendsee Castle in Brandenburg.
Hans Kleissl has received several awards for this commitment, for example the award for the world’s best restoration company in London in 2014 and a few years later the Federal Medal for Monument Protection for his services to the restoration of Arendsee Castle in Brandenburg. Just recently, the Bavarian State Office for Monument Preservation nominated him for the 2021 Monument Preservation Medal for the restoration of the Alte Klosterziegelei in Polling.

VISIONARY FROM THE VERY BEGINNING
Kleissl was way ahead of his time when it came to ensuring originality and high quality standards. Today, he and his team can look back on a wealth of experience that still makes HK-ENGINEERING what it is today: craftsmanship par excellence.
TECHNICAL EXPERTISE SUCCESSFULLY PROVEN IN HISTORIC MOTORSPORT
In addition to restoration and trading, Kleissl has been running its own racing department since 1995, where numerous 300 SLs have been prepared for historic racing and successfully raced in Europe and America.
KLOSTERGUT POLLING
Kleissl’s horizons are not limited to the restoration of historic vehicles. While searching for a suitable location for his successfully growing company, Kleissl came across the ruins of the old monastery estate in Polling, which he renovated from the ground up. Kleissl was already pursuing the idea of “historic vehicles in a suitable setting” at the end of the 1970s. Decades later, this idea became more and more prevalent in the scene with the “Meilenwerk” concept.
OLD MONASTERY BRICKWORKS
In July 2019, after 5 years of extensive restoration work, the listed complex of the Alte Ziegelei, which is now home to HK-ENGINEERING CLASSICS with its event and showrooms, was opened adjacent to the monastery estate around the 300 SL Manufaktur.
Team
EVERYTHING UNDER ONE ROOF
Manufacture, purchase and sale of premium classics and customized services. A team of specialists from all over the world form the heart of HK-ENGINEERING.
To ensure quality at the highest level, restorations at HK-ENGINEERING are carried out exclusively in the in-house workshop – from engine construction, the injection pump department and the body shop to the paint shop and saddlery. Behind this are highly specialized employees from all over the world – each a true master and expert in their field. True to the HK philosophy of “Passion, Perfection, Tradition”, they combine decades of expertise with passion and dedication.
MASTER OF SHEET METAL
The HK body builders manufacture all sheet metal parts for our 300 SL with exceptional precision – whether made of steel or aluminum. Based on years of expertise, they reduce the use of filler and tin – and thus preserve the originality.

CENTERPIECES FROM A SINGLE SOURCE
Our engine specialists work meticulously on reconditioning the heart of every 300 SL. Injection pumps and nozzles are also overhauled in-house. Seamless interaction between these departments is absolutely essential.
IN-HOUSE SADDLERY
The in-house saddlery reconditions seats, interior trim and soft tops in the old-fashioned way, thus guaranteeing the highest possible quality in the finish of the restoration. Our HK master upholsterer is regarded as one of the best in the world.
TO OLD, NEW SHINE
Our HK painters have many years of experience in touching up old paintwork and repainting in accordance with the original Mercedes-Benz color plate.
