I can't tell from the mpc chart recommended by Tobylou whether the 5b Heritage cornet piece is also a Wick. And I cannot tell where the DW5 is in terms of cup depth and throat size. I do note that you are in "the olde country" and other posts suggest some difficulty doing a mpc safari there. But basics first. If the two pieces are Wick, why not see whether Wick makes a deeper cup and more open throat in the same rim size? Since Wick is over there also, there might be some gain in sticking with those pieces. I note the Yamaha 2335. Is that your main horn? My (limited) experience has been that they don't blow very open. I think someone else thought this could be a variable also. But we're not in this thread to suggest other horns.