I love it when somebody get ambitious & I get to watch!
Looks like someone didn't re-attach your carb vents. Most think the vent should be run thru the bottom of the airbox & clipped about 1" below the bottom. No filter needed.
If it isn't all together yet you can plug the vents with the following parts.
Bolt & copper seal to plug manifold vacuum ports, P/N's are as follows:
M6x10 HH Collar Screw 0015060103
Cu-Seal Ring DIN7603 (6x10x1 Copper Washer) 0603061001
Use Blue Loctite or equivalent.
If you use these you don't have to worry about the rubber caps deteriorating & leaking in the future...