Washboard guesswork!

OK, So I've been to the DIY store, bought a sheet of ply, cut out the washboard, cut the hole and mounted the compass..... fits lovely..... The big question, is will it fit the companion way?..... extremely unlikely I'd say... the measurements are getting very vague with time.... so theres a hell of a lot of guesswork there..... I should imagine however, that we'll find a way to jury rig it somehow or other....... Realised that having the battery for the engine at home on charge allows me to get the laptop power system set up, so thats one other task for this evening..... Its looking dangerously like I might even be ready for the weekend!