The mesh filter is a small dome that snaps onto the top of the float seat. You cannot see it in your pictures because your float seat is installed in the carb. I had a bitch of a time removing the float seat from my carb and destroyed it in the process (which is one of the reasons I had to get a carb kit).
Before you convince yourself that the hidden screen is at fault try this. Take the float pin out (in the direction of the arrow!). Then remove the hinge and float needle. Squirt some carb cleaner into the carb via the fuel line. If the filter is clean you should see the carb cleaner flow freely out the top of the float needle seat (and all over your pants). If the cleaner does not come out your screen is likely blocked. I'd let the cleaner sit there a while and with some compressed air blow it back and forth by alternately forcing air up the float needle seat and then thru the fuel line. Take your time, you can clean the screen without taking the float needle seat out. Sorry this is hard to explain but really a simple process. Remember there is only one way for fuel to get into the carb and that is by going thru the fuel line and then past the float needle into the bowl. You have to make sure the path is clear before you go any further.
One note... in your 2nd picture you see that long thin brass tube just south of the air needle? Well that feeds fuel to your choke circuit. When you put the bowl on the carb the brass tube goes into a cylindrical chamber in the bowl. At the base of the chamber is a small hole that allows fuel to flow into the chamber. On my carb this small hole had become plugged with varnish and my bike would not start cold until I finally unplugged the hole. I took the carbs off 3 times before I discovered this!
Stick with this, if carbs are your problem once you get them sorted out your bike will run like a champ.
John