To me, the key to this may be Jungletown Showboat. As far as I know, there are only two 5 page apeparances of that feature, Dynamic Comics #14 and 15. Dyanmic #15 is different, so this isn't a reprint of that. We don't have a complete copy of #14, so that can't be checked. If this turns out to be a reprint of the story in #14, then this means it is probably some reprint book. If not, it's a new book that we know nothing about.
Another clue to investigate is Crime on the Run. Keltner is very specific at differenciating the title variations of that series, and in Punch #20, it was MANHUNTERS - Crime on the Run. There is no mention of Manhunters on the title page. "Crime on the Run" appeared in Dynamic Comics #23, Snap Comics #9, and Punch #11, 17, 19, and 20, but none of those can be checked to see if this is a reprint.
All of the other feature page counts match Punch #15, so it could be a 48 page version of that. Another possibility is it was meant to be the final issue of Punch, but was never distributed, and wound up hitting the stands in some other cover. We've seen this with Rural Home titles.
-Eric