Here's a link to an exploded view for the LP-27
https://www.google.com/url?sa=t&sour...ZQDgM3XcpB2KJK
As you can see, the only difference between the 68 & 73 is the LH cup.
Therefore, if you found a 68mm version, you could try to reuse the old, brittle, likely to break old cup.