Well seems to me seeing as how a an A55 is piston port, a header is not a big deal to make. Any old exhaust pipe bent right would work I should think. Could even make one out of copper tubing and solder if you really wanted too.
The A35 is a whole other story. Its a much more common engine, I think there are only a handful of A55 riders on here and almost everyone has, had, or has a buddy that has an A35 on something.
The whole reed valve thing makes it a little more complicated.
Before I found a bunch of daelim intakes I was looking a fabing one. My criteria was an inner diameter of 19-21mm and an outter diameter of nor more than 24-26.
I was looking for some kind of pipe L union that could be welded onto a piece of 1/4 sheet steel with a 20mm hole drilled/cut in it.
Then I was going to hose mount a 19mm PHBG knock off to it,
I was going to test it out for a couple hundy miles and if it worked out and go from there.
I am still thinking it has to be done, because daelims can only go to about 17mm ID, and 19 is pretty much a minimum.