The Japanese soldier episodes have an anomaly and perhaps reveal the numbers aren’t actually production numbers but are probably subsequent episode titles.
Three episodes don’t include numbers at the end of the episode so I’ve guessed their order through continuity.

Season 1
1625-0701 Voodoo Something to Me
1625-0702 Good-Bye Island
1625-0703 Two on a Raft
1625-0704 Birds Gotta Fly, Fish Gotta Talk
1625-0705 Home Sweet Hut
1625-0706 Good Night, Sweet Skipper
1625-0707 President Gilligan
1625-0708 Wrongway Feldman
1625-0709 Diogenes, Won't You Please Go Home?
1625-0710 Three Million Dollars More or Less
1625-0711 Sound of Quacking
1625-0712 St. Gilligan and The Dragon
1625-0713 The Big Gold Strike
1625-0714 Water, Water Everywhere
1625-0715 Waiting for Watubi
1625-0716 Gilligan Meets Jungle Boy
1625-0717 Plant You Now, Dig You Later
1625-0718 Angel on the Island
1625-0719 So Sorry, My Island Now
1625-0720 Little Island, Big Gun
1625-0721 X Marks the Spot
1625-0722 Big Man on Little Stick
1625-0723 The Return of Wrongway Feldman
1625-0724 How to be a Hero
1625-0725 Diamonds are an Ape's Best Friend
1625-0726 Music Hath Charm
1625-0727 The Matchmaker
1625-0728 They're Off and Running
1625-0729 New Neighbor Sam
1625-0730 Forget Me Not
1625-0731 Three to Get Ready
1625-0732 Physical Fatness
1625-0733 It's Magic
1625-0734 Good-Bye, Old Paint
1625-0735 My Fair Gilligan
1625-0736 A Nose By Any Other Name

Season 2
1625-0751 Smile, You're on Mars Camera
1625-0752 Gilligan's Mother-in-Law
1625-0753 Agonized Labor
1625-0754 Castaway Pictures Presents
1625-0755 The Little Dictator
1625-0756 You've Been Disconnected
1625-0757 Beauty is and Beauty Does
1625-0758 The Sweepstakes
1625-0759 Mine Hero
1625-0760 Quick Before it Sinks
1625-0761 The Chain of Command
1625-0762 Hi-Fi Gilligan
1625-0763 Nyet, Nyet - Not Yet
1625-0764 Don't Bug the Mosquitoes
1625-0765 Erika Tiffany Smith to the Rescue
1625-0766 Gilligan Gets Bugged
1625-0767 Not Guilty
1625-0768 Gilligan's Living Doll
1625-0769 The Postman Cometh
1625-0770 Love Me, Love My Skipper
1625-0771 Forward March
1625-0772 Seer Gilligan
1625-0773 Ship Ahoax
1625-0774 Mr. and Mrs. ???
1625-0775 The Friendly Physician
1625-0776 Feed the Kitty
1625-0777 Operation: Steam Heat
1625-0778 Will the Real Mr. Howell Please Stand Up?
1625-0779 Ghost a Go-Go
1625-0780 Allergy Time
1625-0781 "V" for Vitamins
1625-0782 Meet the Meteor

Season 3
1625-0501 Voodoo
1625-0502 Gilligan, the Goddess
1625-0503 Pass the Vegetables, Please
1625-0504 Take a Dare
1625-0505 Where There's a Will
1625-0506 Gilligan vs. Gilligan
1625-0507 Hair Today, Gone Tomorrow
1625-0508 Up at Bat
1625-0509 Ring Around Gilligan
1625-0510 Gilligan Goes Gung-Ho
1625-0511 Topsy-Turvy
1625-0512 The Producer
1625-0513 Man With a Net
1625-0514 The Secret of Gilligan's Island
1625-0515 The Kidnapper
1625-0516 All About Eva
1625-0517 And Then There Were None
1625-0518 The Invasion
1625-0519 The Hunter
1625-0520 High Man on the Totem Pole
1625-0521 The Pigeon
1625-0522 Splashdown
1625-0523 Court-Martial
1625-0524 Our Vines Have Tender Apes
1625-0525 Lovey's Secret Admirer
1625-0526 Gilligan's Personal Magnetism
1625-0527 The Second Ginger Grant
1625-0528 Bang! Bang! Bang!
1625-0529 Slave Girl
1625-0530 It's a Bird, It's a Plane, It’s Gilligan

Can I aks why a few of those were red-lettered..:-)

Sure Steve. Those are the three episodes with no numbers at the end.

The Japanese soldier episodes have an anomaly and perhaps reveal the numbers aren’t actually production numbers but are probably subsequent episode titles.
Three episodes don’t include numbers at the end of the episode so I’ve guessed their order through continuity.

Season 1
1625-0709 Diogenes, Won't You Please Go Home?
1625-0719 So Sorry, My Island Now



Of course this is only a guess, but perhaps the reason for the anomaly is because the episodes "So Sorry, My Island Now" and "Diogenes Won't You Please Come Home" both contain scenes shot by Vito Scotti as the Japanese Sailor, and one is 709 and the other is 719. So perhaps whomever was cataloging the shows simply got the two confused, creating the error.

That's a logical explanation. Human error wouldn't surprise me.

Of course this is only a guess, but perhaps the reason for the anomaly is because the episodes "So Sorry, My Island Now" and "Diogenes Won't You Please Come Home" both contain scenes shot by Vito Scotti as the Japanese Sailor, and one is 709 and the other is 719. So perhaps whomever was cataloging the shows simply got the two confused, creating the error.


Going over those, the first two seasons have numbers in the 700s and the last is in the 500s.

Boy, those episodes sure got out of whack releasewise, at least, ignoring the above 700s followed by 500s deal. Including "Gilligan, the Goddess", then the last mentioned as "Goddess" was last broadcast. But as I have said before, Schwartz was listed as creator-producer, but not executive producer [a temporarily discontinued title] while later he's back like in 1964-65 to being executive, under his "CREATED BY" title, with former associate producer ROBERT L.ROSEN as producer.

I never noticed the 500/700 numbers before. It does seem strange it wouldn't have gone say 500, 600 and 700 for each season. And I've wondered myself why they held off "Gilligan, the Goddess" for so long.