This is what I used for my cog loco: LGB trolly posts and wires:
Standard Catenary Mast 56400
Standard Catenary Mast with wire 56401
wire 6201 (old number) this item is not in any of the more recent (post late 1990's) catalogues.
Based upon the new numbers for the masts, my guess is that the new number for the wire is 56201.
I have no idea if and where any of this material is available.
Chuck N
Standard Catenary Mast 56400
Standard Catenary Mast with wire 56401
wire 6201 (old number) this item is not in any of the more recent (post late 1990's) catalogues.
Based upon the new numbers for the masts, my guess is that the new number for the wire is 56201.

I have no idea if and where any of this material is available.
Chuck N