I am watching your duplicator come together with great interest.

Starting out carving stocks by hand, it would take me about a month to do just one working at the bench in the evenings.

I too built myself a duplicator and now a LE fore stock can be roughed out and a first fit up done in a day if I get motivated.

But finding time to get into the shop is the challenge. Life gets in the way sometimes.

It seems that the heavier and more rigid the duplicator, the more accurate it is making a copy.
I got the chance to check out a couple of commercial units ($$$$$$).
Built heavy like a machine tool, they probably weighed in at over a ton.

The only thing that I can comment upon is that you will likely need to put some form of brush wipers on the carriage to prevent the wheels from bumping along the rails over wood chips. Those chips go flying and get into everywhere.
Either that or simply have a brush or an airline ready to blow things clear.
Duplicators can create a lot of dust and crap, very messy for the corner of the shop.
They do however produce buckets of walnut sawdust that is great for use as floor-dry to soak up oil spills etc..

My rig uses linear bearings running on one inch centerless ground bar in X and Y directions, they have rubber seals to keep the sawdust out.

And what is happening to the word-wrap feature of the text on this page??? Wot I see ain't wot I get. One paragraph is displayed as one line.