Darn you, Ralph! (Pah-rum-pa-pum-pum)
Without a single note in the file (Pah-rum-pa-pum-pum)
I've got it stuck in my head (Pah-rum-pa-pa-pum)
Loaded up your first file in Composer 4 and arbitrarily added a page break at bar 20 to let me see two pages of Page View.
There was an extra Page Text with just the "<page>" in it at the bottom, set to display on all pages. Removed that and that left a Page Text with "Page<page>", set to display on all pages. Reset that to "Display on first page only (CTRL-1)" Also added a space to the Page Text, "Page <page>".
On the new, arbitrary page 2, the 1st page number (at the bottom) now no longer shows. The top right page number is already properly set to "Display on all pages except first (CTRL-2)".
However, both your arrangement credit and the author/composer credit Page Texts are set to "Display on all pages". Changed those to "Display on all pages (CTRL-A)". Changed those to "Display on first page only (CTRL-1)" and suddenly, all is well.
Removed the arbitrary page break I added and I think the file's where you want it. (Pah-rum-pa-pum-pum).
David