Schwinn Experts Please Advise - 2nd Picture link updated

[GTs58]

1) Schwinn Cruiser 5 - Yes, it does have the high flange on the hub so it's a Cruiser 5. Serial # HR563921 Badge #2520

Here are some pics. Are the forks correct? From my research they switch the design to the surfboard in 1980. Is that right?

I'm breaking it down and cleaning up this weekend. (Looking for a Cruiser 5 Chain guard)

https://imgur.com/a/QM8ye

2) Unknown Schwinn - I thought the same thing based on the forks, headset, and other mismatched parts. Also the double frame area that connects to the main frame could look like a thicker weld from too much paint. When it's sand blasted I'll get a better look at the frame.
* What is throwing off is that found the Serial # HB216660. It references a 1966.
http://schwinncruisers.com/schwinn.php?serial=HB216660

Would they have stamped the serial numbers at the bottom of the bike near the sprocket at that time? (Non sprocket side)

https://imgur.com/a/tcAAj

That serial number on the unknown is not a 66 SN. To many digits and the 66 number is still on the dropout. Schwinncruiser.com gave you bad info which is typical for that site. I would guess this is a 90's frame. Schwinn did not build frames with joints like that during their last days. Even the Murray built Schwinn frames didn't look like that.

The surfboard darts were on the 1981 Cruisers and the 80 model had the standard dart.