you also quoted only a part of my post and omitted the part which said that it was not a 440 for sure. The post which was deleted (presumably by the poster) stated it was a CV-240. It actually was but prior to conversion, probably when still on the production line. I said that I had even seen references to it as a CV-440 and added that it definitely wasn't
The aircraft in question was never a 240. 131D models were based on a mix of 340 and 440 airframes, some of the 131's were converted civil airframes and some new builds. ZS-BRV was a new build 131D airframe and civilianized as a 340-79 in accordance with its TCDS.
Re certification, TCDS,
Type Certificate No. 6A6 (Transport Category, CAR 4b, effective July 20, 1950, and Amendment #1, #3, and #5, except smoke detectors not installed in cargo compartments
Re auto-feather, TCDS,
Ferry permits may be issued to all Model 340 aircraft on which the automatic propeller feathering system is inoperative. Continuous operation with the automatic propeller feathering system inoperative can be accomplished on some Models in accordance with Appendix "C" of the FAA Approved Airplane Flight Manual. Operating procedures, power ratings and performance data contained in Appendix "C" of the Approved Airplane Flight Manual applicable to the CB3/CB16 engines may be used for the CB4/CB17 engines.
Drag from the cowl flaps must be significant, did see a report years ago when a crew found themselves in the same predicament as this, feathered prop and fully closed the cowl flaps on the operating engine in an endevour to gain performance for a quick circuit while placing their faith in Mr. P & W to withstand the abuse. They made it.