Valve Covers For Angled Heads In A 231 V6?

I recently purchased a 1970 CJ5 and I can't seem to find the right valve covers for the life of me. It seems the engine was swapped at some point by a previous owner. The person I purchased it from thought it had a 225 Dauntless V6, but... the block casting number is 1249432 which should be a 1975-1976 V6 231 Odd Fire (I think?).

The engine head casting number is Buick 1249175.

What I can't figure out, or find, are valve covers that fit these heads, which have an angle on the front left and rear right corners, instead of a radius (see picture).

What engine am I dealing with, and what are my options for valve covers?

When I bought it there were some Moroso valve covers that didn't have angled corners so it leaked terribly. I tried the Offenhauser 5881 covers but the engine is too close to the firewall to make those work without cutting into the firewall. They seem to fit otherwise, and what confuses me are the Offenhausers are supposed to fit the 225 Dauntless V6.

Thanks!