I had a similar dilemma with needing to punch 9x12 inch pages to fit the Harris Citation 2-post album. I also get the Vario Grande sheets (which are 9-1/2 x 12-1/4 inches) and trim with a guillotine paper cutter) to 9 x 12 inches to fit the Citation, and need to punch new holes to fit the post spacing.
I discovered that most 3 hole paper punches available are either "fixed" for 8-1/2 x 11 inch / 3-ring binder spacing, or if adjustable its by being able to move the posts to certain fixed positions and none of the options aligned with the hole spacing I needed.
I often check out rummage sales, thrift shops, and school/library/public entity surplus sales, usually just seeing what's there but often finding something interesting, including the two paper punches below.
I have a Mater Products Series 25 punch. While I'm using it just for 8-1/2 x 11 inch paper to make holes for 3-ring binders, it is adjustable for up to a 15 inch high sheet. The 3 "punchers" can be moved to any spot in their range by loosening the round bolt head. I wanted one that would just punch 2 holes (corresponding with the 2 posts in the Citation album) and there didn't seem to be an easy way to remove one of the three "punchers".
I then found a Bates paper punch which can be adjusted for up to a 20 inch high sheet. By loosening the wing nuts the "punchers" can be moved to any spot in the range. I was able to take off the snap ring (on the left of the rod) and pull the rod to the right so I could remove one of the "punchers" (pictured off by itself). This provides me with a 2-hole paper punch that works perfectly for 9 x 12 inch card stock and the Citation 2 post album binder.