Fit and finish on those legs is approaching Museum quality! Nice work!
Here's an alternative for you. Rather than holdfasts, check out Jorgensen's hold down clamps. I have four of them on my traditional bench and also use them on my MFT and other shop tables. They work great and will hold just about anything TIGHT to the bench.
https://www.amazon.com/1623-HOLD-DOWN-CLAMP-3-Inch/dp/B0000DD1RD
I contacted Jorgensen and ordered additional bolts that drop into countersinks in my bench. That gave me more clamping locations. They ship with a cotter pin to allow them to more permanently stay in place connected to the bolts.
On the MFT, it's easy to get bolts, wing nuts and fender washers and just stick them through the holes, slide the clamp over them and tighten the wing nut underneath to secure the clamp for repeat work.
Personally, since you are invested in FT, I'd go with 20mm holes if you think you need them on the new bench. Mine has traditional bench dogs from when I made it 35 years ago!
Here's an alternative for you. Rather than holdfasts, check out Jorgensen's hold down clamps. I have four of them on my traditional bench and also use them on my MFT and other shop tables. They work great and will hold just about anything TIGHT to the bench.
https://www.amazon.com/1623-HOLD-DOWN-CLAMP-3-Inch/dp/B0000DD1RD
I contacted Jorgensen and ordered additional bolts that drop into countersinks in my bench. That gave me more clamping locations. They ship with a cotter pin to allow them to more permanently stay in place connected to the bolts.
On the MFT, it's easy to get bolts, wing nuts and fender washers and just stick them through the holes, slide the clamp over them and tighten the wing nut underneath to secure the clamp for repeat work.
Personally, since you are invested in FT, I'd go with 20mm holes if you think you need them on the new bench. Mine has traditional bench dogs from when I made it 35 years ago!