I might want to try and make this part, but I have no idea how 
It is a bastardized clip-on for a 35mm fork tube.
At work we have a cheap laithe/drillpress/mill combo machine.
I’m not sure its really worth the hassle.
I could buy pretty ones for $150, or weld some 7/8" tube to a metal sleeve for really cheap. ( I am really cheap, I might add)
I made a quick sketch after looking around for clip-ons.
I’m thinking the hardest part is the .875" hole at a 7 degree angle.
There is no issue making those parts out of Al but you are probably better off having someone else do it from the sound of things.
Why would you not just buy some though? This makes little sense to me. Crap, I have clip ons in my basement.
Between time, and materials, you’re not going to do it much cheaper than you can buy new ones for, and if you were savy you could prob. find cheaper ones than you could buy that much Al for.
I’m thinking this is the cheapest way around it.
Or I could spend the $45 for clubman bars. I’m not sure I like the look of them though.
The fact that I can’t do it is sort of why I pondered making some.
That much aluminum is going to cost you $50 or more.
Do you have a machinist to show you what you are doing?
Probably not worth your time.
$50…
I’ll have to wait to find “scrap” then 
EDIT.
These are the pretty ones.
If you’ve never done it, you’re going to mess them up the first time around too 
Just buy them.
That right there is what I do best 
+1 that is a not a simple part to make + its kind of important that you don’t fuck it up.
http://www.google.com/products?q=clip+ons+handlebars&hl=en just buy them… ranging 60-150 bucks… brand new.
why reinvent a shittier wheel… <3
Well, and without CNC (or a rotary table and some serious skill) you won’t be making those pretty rounded corners, and you’ll need a boring bar for that hole.
^I was going to say, making a functioning set should be fairly simple but they will look pretty sad. lol
