Apart from the series of JPs built by Joe Potts, there were only three other 500cc racing cars built in Scotland - Roy Clarkson built an Iota, Alex McGlashan built a Marwyn and in Leven, Fife two brothers and their friend built a very professional looking car called the MHM 500. They were Jock (JB) and James (JC) Moncrieff and their friend was DY Henderson.
The car was constructed from a modified Fiat chassis, which may have contained parts from a Marwyn as period reports state the Moncrieffs had purchased a Marwyn. However, the chassis was indeed a Fiat and this was recently confirmed by a friend of the Moncrieffs, Alex Fairbairn, and also by the October 1951 advert when the car was listed for sale. The engine was a tuned Triumph Speed Twin, rear engined and, from the look of photographs, driving a solid axle supported on leaf springs. This axle looks very like a Marwyn item. The MHM had a very neat and professional looking aluminium body, which fully enclosed the car. Jock worked as a mechanic at Murieston Garage and the MHM was a very well built machine and was always neatly prepared.
The MHM 500 (Moncrieff – Henderson – Moncrieff) was ready for action by the Autumn of 1948 and it was driven at the September Bo’ness hill climb by Jock Moncrieff who won his class, beating the Marwyn of the very experienced Alex McGlashan. This early success was not to be repeated though and despite several outings at Bo’ness, The Rest and be Thankful, sand racing at St Andrews and circuit racing at Crimond and Winfield, the car proved to be rather too heavy and underpowered. Alex Fairbairn also remembers the Moncrieffs taking the car down to Silverstone but there is no record of it competing there.
Jock Moncrieff emigrated to South Africa in 1952 and advertised the MHM for
sale in the Winfield race programme of October 1951 for £250. It is not
known who bought the car but it reappeared at Bo’ness in June 1953 re-bodied
and re-named as the Hammond 500 Special and seems to have been converted
into a two seater, rear engined sports racer. It crashed in practice and was
unable to continue. The MHM – Hammond 500 was last seen dumped ignominiously
on its side in the rear of a truck in the Bo’ness paddock. It made no
further competitive appearances and has disappeared without trace.
Our thanks to Kenny Baird, if anyone has any more details or photos, please get in touch.