O.K. ;

I'm glad you mentioned the stripped 6 MM studs .

The missing gasket is very thin paper ~ you can make one easily @ home .

The best bet is to purchase a new insulator from your local Honda dealer who'll mistakenly insist it's discontinued when in fact , it's just superceded , ask for -any- CT90 insulator , it'll fit *perfectly* and cost less than $10 .

Or , Jack @ Dr ATV (Beatrice Cycle) will  have it in stock .

I prefer to reward Honda for still making 45 year old Moto parts available .

The 6 MM studs often pull out , just go get some 6 X 1.00 X 40 MM long flange head bolts and insert them in the carby , then use 6 MM flanged nuts and some 6 MM flat washers on the intake manifold side , this gussets both sides and prevents the carby's flange from warping do to heat soak .

If all else fails , the newer design round bowl CT90 carbys are available all over for $30 and that'll fix your problems permanently .

Have fun and remember : the hardware used , matters greatly ! .