The bright trim strip is item 23 in the image below, secured by rivets (item 24). It is used on MGA roadsters the have vinyl covered dash panel (not the standard 1500 or 1600 roadsters).

On 10/1/2012, Colin Manley wrote:
"I bought one from Moss and the fit was bad and took a lot of rework to get an agreeable fit".

On 10/1/2012, Harry Buberniak wrote:
"I found an easy fix. Just trace the bottom of dash on a piece of wood, cut the wood on trace line, then put all in a work mate, spray metal strip with Teflon, and squeeze the wood together. Check out the photos".