I don't think the fixed steady for the Cowell will fit, the Cowell has a 1.75" centre height against the 2.00" of the Flexispeed Meteor 2.
Years ago I did start making a fixed steady from a piece of 1/2" steel plate, but never finished it as I acquired another machine. I still have the unfinished parts in a draw.
I did manage to make a screwcutting setup, this was based on the design in L.C. Mason's book "Building a Small Lathe". I used his idea for the locating pins in the gears.The Flexispeed arrangement did not allow me to cut some pitches that I needed. I cut my own gears from aluminium plate on the Flexispeed itself using a single point cutter in a clockwheel style cutting frame. 24DP from my notes, it was about 40 years ago now.
Funnily enough, I pulled the Flexispeed out about a month ago to cut some threaded adaptors in brass, 3/8 x 16 BSW, 1/2 x 26 Whitworth form and 5/8 x 27UNS. The leadscrew was kept engaged and the lathe pulled round by hand both for the cut and reversing, the slowest motor speed is far too fast. I also pulled it round by hand for parting off, takes a bit of time but far less "exciting".
Neil