I'd try that one, Martin, but cut accross the middle, so the bottom of the gas check is closed.
That is, from the botom of the fingers, across the second upright posts, and trimmed so the surface is flat.

One should be cup-up, to cradle the ball and hold it in the centre.
Place another on top of the powder, cup-down as a gas check, then whatever fiber wad is needed between to get the right height with the ball to crimp- either folded, or roll crimp. I use a folded crimp.

I would use a high velocity load listed in a manual for 1 1/8th to 1 1/4 oz. of shot and work from there, developing the load further for velocity and accuracy. Accuracy wins out over velocity, but I found the higher the velocity, the better the accuracy.

With a .690" ball, you should be able to get 1,500fps, very close to what a 191gr. 2F black powder charge will give- but - the smokeless load will kick perhaps only 1/2 as much.

That wad looks like it will work very well. It is soft and plyable in appearance.