Best way to adjust?

My regular Gonzalez 2¾ reeds are not available right now and they have a delivery date of a couple of months, so I'm stuck with either trimming a bit off 2½s with a reed cutter, or shaving down 3s with reed rush. I've tried both methods and I'm not getting good results with either. I get the closest approximation to a 2¾ feel by trimming about ½+mm off a 2½, but it's not a good end result - it just feels strange, but that may be me not the reed. I've totally failed with the reed rush. All I get after shaving down a 3 is a reed that sounds horrible and doesn't last 5 minutes, so I guess I'm doing something wrong there.

So I wondered what the best advice is to manufacture a decent playing reed between a 2½ and a 3, cut down the softer one or shave down the harder one, and if its the latter, how is it best done?