Thanks for the pointer to the Mint price lists at the NNP. I recommend the 1867 pamphlet to anyone interested in patterns and proofs after 1866. There is a discussion of how the minting of proofs and patterns were to be regularized, with patterns available only in the year marked and proofs for only one year beyond the date.

Read between the lines and proofs were made on the medal press from 1867 - proof coinage is referenced as being part of the separate processes used for medals vs. business strikes.

I believe it may have included out of date information at the time it was distributed. Note that the flyer carries a printed date of 189, with the final numeral to be entered by hand, a not unusual situation for legal or financial documents of the time. However, the text states that proof coins were being struck with a screw press. I believe that practice ended in 1893, when the screw-driven medal press was replaced with a hydraulic press for coining proofs.

The flyer was most likely printed sometime between 1890-93, and a quantity of this document still remained on hand when the illustrated example was sent out in 1898.

The text appears to predate introduction of an hydraulic press for striking proofs. That is not unusual. The Mint often used forms internally and for external communication until the supply was exhausted. Records indicate they were parsimonious in using forms, copybooks, flyers and other materials. David Lange's comment is certainly accurate.

I might further add that we do not know on what date the first proofs were made on the new hydraulic press, or if both old and new presses were used simultaneously. As most are aware, new equipment often requires a lengthy break-in period and considerable "learning-curve" for the operators.