Recently an old friend of the family passed away and while going through his things we discovered something unusual. He was an amateur racer for many years and had acquired a clipboard with two attached stop watches. The units are fairly large, about 4 inches square, with silver plastic case and relatively large digits. They're powered by an AA batteries and keep great time. They're labeled Heuer and are in fairly good shape except one battery cover is missing.

Are these genuine Heuer pieces? Where would I get a battery cover? How rare are they?

Thanks,

Dave