The problem
I have a leak in the upper half of this thermostat housing on this T5 engine of a Volvo between parts 28 and 27 of the diagram below. I disassembled things today and found a metal gasket (part 26) which got a little deformed and bent upon disassembly. I went to look for a replacement gasket but found it to be discontinued. They instead sell the entire two part housing kit which has a gasket of its own which are both still for sale. In the sale page there's part 26 which is the gasket I am seeking but which has no corresponding part number on the website: https://usparts.volvocars.com/a/Volvo__XC90/__5702956/Coolant-pump--thermostat-and-cable/GR-365311.html.
Here's an image of the full two part housing kit, the seam that I trace with the orange lines is where the gasket is found, the leak is dribbling somewhere on the bottom on the opposite bottom corner from where the blue arrow points.
Here's a photo of the upper half removed from the block and with the gasket visible and bent and showing some metal corrosion as well as fragments of its gasket material that got brittle and fractured off.
Here's a photo of the bottom half still attached to the block and with gasket material broken off and left behind.
What are my options
I'm trying to consider what my options are to eliminate the leak. I'm considering mating the two halves directly with this Permatex Water Pump & Thermostat Housing Gasket Maker 22071 after thoroughly cleaning and polishing them both with a 3M Roloc Bristle Disc followed by some brake cleaner spraying.
I'm also soaking the metal gasket in gasket remover and have been scraping and abrading the old gasket material away hoping to straighten it out polish and clean it and apply the above gasket maker and sandwich the housing pieces back to how they were and effectively refurbish the metal gasket since I can no longer purchase one. Is there any added benefit to doing that? I'm hoping it may create a more enduring seal but maybe it would just be a waste of time? Are these metal gaskets better than gasket maker or are they just time savers at the factory to get a seal established very quickly as opposed to fiddling around with gasket maker and wasting factory time during assembly?