Some general unknowns about my kz750

This is mostly chassis related-- so I'm posting it here. But I have a few unknowns about my new bike, and the Clymer manual hasn't given me the answers (or, I just don't know where to look yet.)

First up:

I'm going to assume that Kawasaki's aren't meant to be held together with zipties. What are the specs of the missing hardware here? And is there anything missing besides a seemingly obvious bolt?

Next:

Here I have a dent that I will try to repair. But, I noticed this chunky cement stuff. Is that just pitted filler? Any idea what the PO was trying to do here? There's more on the other side of the tank, like maybe they were trying to make the badge mount flush or something.

Ok, not chassis related, but:

Is this a fuel filter? And, it leaks profusely when the fuel switch is in Prime. Like, not drippy... but pour-y. Just some insight into what I'm trying to troubleshoot and fix here would be nice. I couldn't quite get an angle to see what the actual connection looks like.

[EDIT]I'm referring to the cylinder object connected to the fuel hose there. This is a pic aimed along the back of the carbs. It leaks from the connection to the carbs.

Also, just beneath that, you can see a nitrile glove stuffed into the breather port. The PO added pods and I guess just decided the breather hose wasn't important and the port doesn't need a filter. What should I do to repair that? The Clymer talks about maintenance, but I can't make out from the illustration if it is just a short hose or some sort of rigid part I need to replace.

Last, but not least:

That's the back of the ignition switch. Is there supposed to be some sort of cover on that? Or is this like "forgot my keys... let's just find a soda can tab and get this baby running" mod? What should I do about that?

You need a m6 bolt with a 10mm hex head and a washer,.
The tank was damaged in a wreck. Clip on bars or a turn signal.
You need new fuel line and a filter.


There should be a cover, I can see the screw holes.
Steve

The previous owner mentioned he dented the tank with clubmans... but I'm wondering what the crusty bits are.

The crusty bits are bondo or something & not part of the original tank.
Some of the fastener sizes are listed in the parts diagrams at Kawasaki.com or partzilla -- fuel tank bolt = M8 x 30.
Install new fuel line & an in-line fuel filter (5/16"). some clear filters get deteriorated by ethanol.
Drain & clean the fuel tank and check that the petcock screen isn't clogged with rust.
The ign switch cover plate is missing. Install the plate or get either a good used switch or new.
I would install the stock airbox. It helps to list the specific 750 model in your signature.

Here's a site w a pdf manual & wiring diagrams. mbsween. bike-night. KZ750L3 page
Scroll down & click "The Bible" link. ......... search tags mbsween KZ750L3.
Note: some of the wiring diagrams are mislabeled in the links: the 1981 Ltd is an H2, the 82 is an H3, & the 83 is an H4.

Time for a different tank. The crusty bits is what's left of a attempt at covering the badge bracket. ANOTHER reason PO's suck.
Steve