Driving and wheeling

My "new" wheelchair must fit in the lockdown mechanism in my van and my old one must fit also. I always went to my mechanic for the bolt to be drilled into my chair and I was mostly fine. Now the company that did it was taken over by a company that wants is concerned by liability and making money. They are not too willing to ensure that both chairs fir in the same lock. They offered to try by securing the bolt then trying it with the van. It doesn't meet with their approval they will just remove it for $200 or refuse to make adjustments. He guy says would I rather have an accident if it's done wrong? First, I wouldn't even consider any chair that is not exactly like the one I have now, so I can drive with both. Second he should give me some credit that I am aware of this issue. He assumes that since the chairs are from different manufacturers they would be different underneath. That isn't true. The evaluator was urging me to purchase a wheelchair that was nothing like the previous one. She wouldn't even look mat my van when I asked. If I said yes and it didn't work I'd be stuck; there could be no trial period. These are the experts?