I did the same, except black on black.
But one thing I recall, is that the seat belt material is 2" while the original straps and the front clamping depression are 1 1/2". End had to be cut down to fit. I think I included pictures in the EGV107 thread on top replacement.
I at first bought the elastics from a fabric store. But really, it was next to useless. I then bought batten pocket elastic from a local sailmaker. You can also get it on-line from Sailrite.
I added some foam tape where the nylon webbing crosses the bows. Before I did that, there was a hard point and small crease in that area.
One of those jobs that I am glad I tackled, but don't want to do again!
Not a pleasant job, not a physical job - more like stressful aliken to painting a room in your house.
I think if I had to do it again, that it would be more enjoyable
and turn out better.