I recently made few changes to my 1986 Bridgestone 400 and like it very much. You need to find an old Jim Blackburn rack that attaches to the brake bolt (as in the picture) to avoid using p-clamps.

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Here is an old Blackburn rack for the front that also mounts on the brake bolt, no P-clamps required:

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The new 520 is a nice bike and a great choice if you will be doing unsupported, long-distance touring. You could certainly use it to commute but it is a bit like driving an F-250 quad cab to the office everyday. The B-stone would do well w/ a wheel upgrade (700c) and a a brake upgrade (Tektro R538) I am able to run 32mm Paselas w/ fenders and no clearance or removal issues. Good luck whatever you choose!