Yes of course! In fact for non-standard insert sizes, copying the dimensions of your old cover is often the best way to ensure the new cover made will fit well. Here's how to measure properly: Turn your old cover inside out and measure where the inner stitching lines are. If the edges are finished with an overlock stitch (looks like a zig zag stitch), look for the innermost line of straight stitch (looks like ------------) and measure from there.Additional tip: Measure across the middle and also at the sides to verify it's a square or rectangle with 90 degree corners. If the corners are tapered, the middle measurement will be bigger than the length of the side seams. Send your information and measurements via the custom order request form.