TR3 brakes (check valve?)

[mbarre@juno.com (Matt Barre)]

I didn't realize that there was a valve or restrictor in the brake
plumbing on this car.  I am completely redoing the braking system and
was wondering if this is something that should be replaced (are new ones
even available) or can it simply be left out?  I recalled some mention of
this in the recent past but didn't know what it was about till I  started
replacing parts on mine.  I am currently bending the new lines.

TIA,
Matt Barre