I have an Alberti right angle attachment for our VF-1. I bought it on Ebay, but it did not come with the stop block that bolts to the bottom of the spindle.
I priced it thru Koma Precision ($375.00), and from Haas($369.00).
I have a photo from the Koma Precision website. It looks to have a hardened steel bushing, and possibly a blind hole. When we fit it to the machine, the length works out so that the plunger disengages against the bottom of the spindle. I see no reason why the block coudn't have a thru hole.
Comments? Suggestions? Criticism?
I'd be happy to share the sketch when I'm done.
Take a look in the bottom of the electrial cabinet on the back of the machine. 2 of our vf3 came with them .