I need some help on these leadscrews I found .

[belgrado]

Hi, I obtained some of these leadscrews recently (see pics ) + some kind of synthetic nuts with aluminium holders came with them . There is no sign of what brand they are or what type of thread it is .(acme ?? ) They seem to be well made and are probably made out of stainless steel .
The screw has 2 starts , 5 turns per inch , and 10 threads per inch . ( 0.2 " per revolution ) . Diameter is 3/4 inch .
Before I decide to use these on a machine I would like to ask the cnc zone community if there would be any replacement nuts available for them and if these would be a good choice to use in a medium size wood gantry router ( with nice frictionless linear slides ).
Also maybe somebody knows where I could find these in other lenghts .

Thanks alot .

Paul