I tried - a number of years ago when we did a comparison of the 20th C against the CKing DP Deluxe.
At the time there was the view (which to some extent still stands) that the 20thC Vader face was the best around (in numbers) and that combining it with a better ANH style dome would produce a quality ANH helmet.
Anyway we tried it with the CKing DP to try and make a better ESB. The pic's a bit crap as the connection bridges were totally different
I have a CT 20th Century that I fitted with a modified DP deluxe dome cast. I got the dome from a member here. I believe the dome was made longer and made thicker on the edges.
Anyway the two go quite nice together.
Though I believe the 20th Century face and the DP deluxe dome are more ROTJ than ESB, due to the larger chin vent on the face mask and the lack of the Y crease remnant on the dome.
Here are some pics of mine.