Contact Mayville Engineering Corp. [MEC]
I'm sorry -this PC does not have the bookmark.
MEC gives GREAT service, call them and the will ship out to you the chrome colored top really fast! Don't forget extra gaskets and anything else you may need while you are it.
At one time I had 10/ 11 MECs. I used the single stage for all serious competition loads and load testings. I am of the belief even if one gets a 9000, one still needs a single stage.
IIRC last time I ordered a part for rebuilding one bought in a yard sale - I had the part shipped to me within 4 days - COD .
Edit: Here is the addy:
http://www.mecreloaders.com/main.asp