I suppose I should just have it removed.
Anyway, I can vaguely recall someone (either here on on Wiki) posting a solution to the “No input file specified.” problem when running PHP under a custom-compiled CGI when a page is missing to point to custom 404 page.
Provided I’m not entire mistaken (which I may well be), if someone would be so very kind as to point me at the pertinent post/Wiki page, I would be ever-so grateful.