There are a couple of more you may or may not be aware of:
On the expensive side is the 1925 Holland World's Champions Washington Senators. Paul Zahnister is card #9 in that set. According to SCD these cards are 1 1/2 by 3 inches. The player portraits are printed in blue. They were issued in Winnipeg Manitoba (!) which no doubt contributes to their scarcity. A couple of months ago, a PSA2 went on eBay for $750.
On the other end of the affordability scale is the 1975 TCMA 1924-1925 Washington Senators. A little over a week ago a near set (missing one card) went on eBay for $18.99.
Obviously both sets would include Paul's teammates. Of course, the Holland Creameries cards would be extremely pricey if not nearly impossible to put together, but the TCMA set should be cheap and easy.
(NOT MY CARD)