The bolt in the steel pipe is nothing to do with the breather system, it shouldnt be there and Ive no idea why it is, but just leave it and ignore that.
Most vital is the lack of engine tinware, seriously, the engine will over heat if driven anywhere like that
the engine needs removing and building up again with tinware, its not something you can do without.
The oil leak may be down to do with lack of a breather, my guess is there may be an outlet undr the blue tape on the oil filler neck. Connect a pipe to that, you can connect the other end to the pipe stub on the air filter you have.
The fuel filter, as mentioned, isnt in an ideal place, move it to the tank outlet when you get the chance.
But, I see there is at least one fuel hose clamp missing, thats not acceptable, and it looks like a fuel pipe is all rubber and is exiting over the rear of the engine, beware that chaffing may occur and split the pipe.
Honestly, this isnt people being precious over correct year parts or something insignificant, this is dangerous and you may catch fire and/or sieze up your engine. It needs re-doing before it should be driven again.
Sorry