1930s WW2 Military/ Commercial Vehicle Brass Chassis Lubrication Plate

I know very little about this 1930s WW2 Military/ Commercial Vehicle Brass Chassis Lubrication Plate. It shows a schematic line diagram of a vehicle chassis etched on to the brass plate. Think of it as a vehicle service hand book. 

It would have been screwed to the chassis of a 1930s/40s commercial/military vehicle to advise the mechanics when to lubricate the various chassis components. It informs them whether to clean, use oil, fluid or grease, and the frequency; daily, weekly, or monthly.

At the bottom of the plate, (in tiny writing!), you can make out the following:-

• Use War Office Oil M600 in Rear Axle.
• Use War Office Oil M220 at all other points.

This is a great piece for collectors of automobilia, militaria or to frame and hang as a piece of art in the office, study or garage.

It is in reasonable vintage condition. There are scratches on the front and back surfaces, and the brass is slightly pitted in places. 

Approximate Dimensions:- 

• Length: 28cm (~11")
• Width: 13cm (~5.1")