lathe chuck face stop

[Toolmaker51]

You just solved an engineering impasse for me.
I have occasion to need chuck stops. The collection at work is best described [not so] kindly as grisly. Horrendous fits even better. I appreciate the idea of an adjustable unit. There isn't any 'production' volume but the couple dozen this-or-thats are held to a reduced tolerance.
Following your pattern I'll tap 5mm to match space blocks, rather like screw on gauge blocks. Very handy little devils. The other arms will get a 5mm screw for height equalization, zeroed on surface plate and height gauge to the space block.
There is a commercial version of these with magnets on the 3 arms. Nothing I hate more than magnets on a locating device.