Keep a careful eye on it. Often the piston and seal abrasion from full-stroke bleeding as described above will not immediately fail the MC, but it will fail soon thereafter. With the pre-'67 single-pot master, your margin for "oops" on this is basically zero. Best go ahead and buy at least a new master cylinder (better: the parts to retrofit to dual master) now, so you will have them right at hand when, sooner than later, you need them.
