British Lawnmower Museum

The Museum has now become one of the world's leading authorities on vintage lawnmowers and are now specialists in antique garden machinery, supplying parts, archive conservation of manuscript materials and valuing machines from all over the world. The Museum retains a character not often seen in these modern times.

Via the archive section on their website, they offer to use their collection to supply information about historical lawnmowers to enquirers, and they also have an "ask an engineer" section for technical and spare parts queries.