2013 Tundra: I need to replace the wire harnesses and 7-pin/4-pin tow plug

2013 Tundra TRD Off Road with the OM tow package: I noticed this week that the wire harnesses that are connected to the back side of the of the OM hitch (or tow) plugs are in bad shape, specifically the round-shape plugs behind the 7-round and 4-flat plugs. The harnesses' plug contacts (or pins) already have too much corrosion, and some of the plugs locking tabs are broken. I would like to replace both the harnesses and plugs, plus the receptacle (7-round & 4-flat). This receptacle can be seeing in this old thread, but I want to mount it on the OM plate instead of relocating it.
https://www.tundras.com/threads/diy-trailer-harness-relocate.421/

I may have to purchase Toyota harnesses, unless some of you can point me in the right direction since the OM harnesses are quite expensive. Cleaning the contacts and reconnecting the harnesses is not the best way to go about it, since they are too grimy, and have never had terminal grease on them other than at the factory installation.

 

I have only seen the OE replacement for like $250

My harness is fine, but the PO somehow lost the metal retaining clips for securing the receptacle. Really wish Toyota would offer the clips separately. Alas, they have decided against this, so my harness remains dangling.

Suppose one day I tear the damn thing off and have a good excuse to buy the complete harness!

 

Yes, at least for me it would be a good idea to replace it, since sometimes when towing a trailer, the trailer lights and brakes lose power. This does not happen to the rear lights on the truck, which means that the "open" or loss of power to the trailer is happening between the harness and the receptacle under the bumper. What I plan to do for the time being is to remove both the harness and the receptacle to clean all the pins (contacts). This will be a temporary measure because that harness plugs are in bad shape already. Once road salt gets in there it doesn't take long for the contacts to deteriorate.