DHE Vent Rib not noted in Parker Serialization Book

[B. Dudley]

If it was a factory original vent rib gun, the top of the frame will be flat. If the top of the frame at the rib extension is concave, then the vent rib was added after the fact. Either by the factory on a return or by other means.

[Randy Roberts]

You can also take a mirror and look under the rib usually between the 2nd and 3rd post where you may find the last 3 digits of the serial number. If you do not see them it is not the defining factor in the determination process but if they are there it's a good indication it's right. You will probably need a small light, my eyes do anyway.

[Richard Seccombe]

I may have answered my own question in that I didn't realize that there was a photo of the top of the rib with Parker's address on it (unless counterfeited)

Here are the requested photos