I did the same thing as you did to my Cove Stiffee FR (ovalized headtube).
You have a few options:
1 - JB Weld - it is basically liquid metal that you mix like epoxy and glue a headset back into the frame. Hopefully it stays in there forever, so use a headset that is of decent quality.
2 - the tin can option in combination with JB Weld.
3 - used a deep cup headset like the King Steelset or new Syncros
4 - get the frame either crash replaced or warrantied.
I unfortunately had to pay for a crash replacement even though the cause of my troubles was using a Triple Crown Fork on the bike which I was told by the Cove was covered by warranty when I got the frame. I should have got that in writing because I was not pleased having to fork over $400 for my crash replacement frame.
I am now content to only use a single crown fork on my shiny new '04 Stiffee.
Good Luck.
Here is a picture of my new frame built up.
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