The pic of the anal vent shows it right in front of the anal fin. Compare that to the photo on page 5 of 31 in the following paper Description and Relationships of the Longbill Spearfish....:
http://docserver.ingentaconnect.com/...2E5A1BF3DEB8E1
Anal vent is well in front of the anal fin vs that in your pictures. Sorry, but those are clearly striped marlin.
Some other descriptions from the article:
Actually, belone is easily distinguished from such species at
any size. It differs from all Atlantic istiophorids in the anterior placement of the **** and the high number (46-53) of dorsal spines.
T. belone may be readily identified by the following combination of characters: the high number of spines in the first dorsal fin, the form of the spinous dorsal fin, the anterior placement of the ****, the bill length and the form and height of the first anal fin.
The dorsal profile of both the sailfish and the white marlin rises sharply above and behind the eye (fig. 3c). Thus these species have a characteristic dorsal hump in front of the dorsal fin whereas this region is even in longbill spearfish from the dorsal-fin origin to well in front of the eyes, and in smaller specimens to the bill tip.
Note: this is the forehead slope I mentioned. White marlin are very close to striped marlin which would exhibit the same.
Finally, count the dorsal rays in the 3rd pic of this thread "the other fish". I get somewhere between 30 and 35 rays. That's not even close to the 46 - 53 cited in the posted scientific article. It's a striped marlin.