There is a post in "How To" for How to post pix with imgur
http://wellcraftv20.com/community/sh...ad.php?t=22480
Looks like you copied and pasted thumbnails, not the full image.
78s didn't have overboard draining decks.
Probably has a 20" transom, saddle tanks.
I would raise it up to 25".
I did a pourable transom. Look for thread here tagged transom and look at my you tube videos
https://www.youtube.com/watch?v=EEz94NbKCh0&t=2s and
https://www.youtube.com/watch?v=Oe_ZmPOUCNc
Trailers are almost always cheaper to buy new than replace 2 axles, springs, brakes, hubs, actuator, lights, wiring, rollers and u bolts....oh and 4 TIRES.
That said, You gotta make the call based on condition. From what I can see its a double axle, probably long enough unless someone cut the tongue.