The routing of a standard Precision won't accommodate a '51 style control plate because the size and shape are so different. A '51 style Precision has but a very small control cavity because it only houses two pots, and the output jack is located on the side of the body instead of on the pickguard / control plate. So if you want anything out of the ordinary, it's probably gonna have to be a custom job.
Here's what a '54 looks like under the hood:
And here's a standard Precision body:
There are some other pretty elegant options, like maintaining the modern Precision style pickguard like cutting a piece off and mating it to a metal control plate. Yamaha does this on some of their new BB models, and our very own Rod of Regenerate Guitar Works does a very elegant take on this as well on his Regenerator model range.
