1938 Oldsmobile- Running board rubber installation help

[cron1984]

Good evening,

I hope the pictures I attach are helpful. I purchased running board rubber specific to the 38 olds from metro moulded. I’m prepping the steel to glue the rubber on, but I can’t quite figure out the orientation of the mats. The big mat is obviously oversized and pressed to look original, however on both ends there is an etch that says “Do not trim”.  I can’t envision a scenario where I wouldn’t trim this mat down to fit once it’s adhered to the steel. 
My other problem is an apron piece that was included with the lip.  This piece presumably goes on the inside of the running board under the rocker.  I’m trying to figure out if it’s glued on the underside of the running board or on the top. It has a thicker side with a lip. My garage lighting isn’t great so I’ll add some descriptions with the pics. Thanks for any help. 

New rubber. You can see the press where it looks like it would be trimmed. The do not trim stamps are on each ends. 

Do Not TrimAnother angle of the new rubber. 
Apron piece with thicker lip. Apron piece. Cleaned up running boards. Original boards. The rubber was painted over with some flex seal type stuff. 

[JFranklin]

Have you posed this question to the seller? 

[cron1984]

I did. Still awaiting a response.