1996 Ford Escort valve cover gasket replacement

I cannot believe how much I am struggling with what should be a straightforward replacement of my slightly leaking valve cover gasket on my 1996 Escort 1.9 liter.

In hindsight now, with one of the mounting bolts quite loose when removing the cover, I should have tried keeping the gasket, which came off pretty cleanly, cleaned things up, reinstalled the cover, and kept an eye on it, but I tore off the gasket pretty quickly and cleaned up the cover stupidly thinking that a replacement part would be available.

Little did I know that the gasket only comes molded in as part of a new valve cover ($300), that neither Ford nor anyone else I can find has an equivalent replacement gasket, and as a result a groove is left in the cover that seems sure to leak if something is not done about it.

I have only found a Felpro gasket whose technical line recommends filling that groove with a silcone product first. I have tried Ultra Black a couple of times as I thought that is what the tech line recommended, but it seems horrible for this specific task, being pretty thick, leaving holes and gaps in the groove, not drying even after a couple of days, and additional frustrations. Perhaps there is a trick to it I am not aware of.

This should only be a two-hour job even for me and my car has been half apart for more than a week now because of this dumb problem. Any advice about different parts and/or procedures that I could use to get my car back together would be greatly appreciated. Thank you in advance very much.