SurferKris forum posts in last 60 days

That looks mostly like bump and jump though, I cannot tell from that video if you are flying of the fin or not.
There are better videos about this, se for instance below (skip to e.g. around 17 minutes if you want to).

Hard-soap works as a high spot indicator too, but that is more for the two sides and it is not usually needed for the two tapered ends.
Sometimes the black plastic of the fin-head is good enough as an indicator on its own. It gets matte/dull after sanding and then turns more shiny at high spots after a trial fitting in the board.

It is an UNC screw, I have bought a set (20 pieces, 12 US $ in total) of 10-24, 3/4" long in stainless steel ones from AliExpress, works fine.

You could try out the race sails from Severne, since you already have the correct masts (I guess).

I only have two overdrives myself one 8.6 R8 and one 7.8 M4. I do like the R8 one, much lighter than the Race Reflex sails from that time, but the OD M4 doesn't give much advantage compared to a 7.8 race M1 sail that I also have. The Mach race sails are much lighter than the older reflex (race) sails, and they are only a little heavier than the OD. The weight difference is mostly felt on land and a little in the gybes, but the Mach sails have a much better drive and range compared to the OD, in my oppinion. I haven't sailed them on the same day, but I feel that the mach sails have both a better low end and a better high end. They also feel more "efficient" and once up to speed they coast better through lulls. Below 7.8m^2 they only get better and better, in terms of handling and weight, and the 7.0 M2 (race) is a real favourite of mine. So light in the hand and plenty of drive without pushing down on the board, highly recommended. 👍

So if you haven't tried the mach sails before I would recommend/suggest to try them first, before possibly moving to another brand.

PS. I'm 57 years old and around 65kg in weight.