What Deacon said.
Besides, you can't take out some material to make it fit. The clipons are round and when you take out some (the redneck way) you make them oval - and they wont pinch all around anymore.
Clamps like that are designed in a way to keep a little space between both ends, ensuring the bolts are tight and everything is snug. If ends meet, you wont be sure about if it's tight enough or not around the fork legs (with a scaled torquewrench). Furthermore, by clamping them further then they were desinged for, you're also making in them oval, like in the first example.
Chopping some material out and welding it back and god knows whayt kinda hackjobs you can think of are oke when it's your neighbours kid's tricycle horn or sum.. but handlebars on crotchrockets?
You can easily sell them on eBay nowadays with the hipsters #swag #yolo #caferacer #vintage #barnfind tags, probably for more then new ones will cost ya.
Long story short, GET THE RIGHT ONES.
Word of advice, GET THE RIGHT ONES.
Really, don't ride with them.
Are they DIY? the welds on the bars to clamps look to be a little small or dented?