Here is an original condition Otto Link "Master Link" Four Star Model. This piece measures .055" on my gauge.
These are among the earliest brass pieces finished and sold under the Otto Link name when the vogue in design was to have a very large chamber that suited the instrument design of the 1930's. This one has its matching ligature which are increasingly difficult to find.
While this piece is original I notice some wear at the table from many decades of use. Inquire what options are available to counteract this detail.