I've spend some time looking at chronograph bridges on the known A386s (from the Alpha Hands database).
Just, because...well, because that is what one does during a pandemic.

On the chronograph bridge I generally see four different sets of text, only two of which I believe are intended for the Zenith A386:

• ‘ZENITH’, with ‘THIRTY-ONE 31 JEWELS’, and then ‘3019’ above ‘PHC’
  • Seen across all three executions, including all 3 of the Mk 3 production batches. Correct.
• ‘ZENITH’, with ‘THIRTY-ONE 31 JEWELS’ and ‘UNADJUSTED’ text below, and then ‘3019’ above ‘PHC’. ‘PHC’ sits within a rectangle
  • I see these bridges in a few of the 538Dxxx series (Mk 1), but enough to believe they are correct.
• Only ‘SWISS’ with ‘3019’ and ‘PHC’
  • These we find on the questionable xxxD460 pieces, as well as other pieces that have had a significant number of parts replaced. I am not sure if this is a Zenith component, but at the least I do not believe it was originally used for the A386.
• ‘3019’ and ‘PHC’ only
  • As with the above, we find these on the questionable xxxD460 pieces, and others with numerous replacement parts. I do not believe these are original A386 components.
• Lastly, there are pieces that show either ‘400’ or ‘400Z’, with no text
  • Chronograph bridges stamped ‘400’ were used in later caliber 400 pieces introduced in 1987, and ‘400Z’ for pieces introduced in 1998. Neither original to the A386.

More details on alphahands.com, but wanted to share here.