Balance Inquiry

Greetings!

I live in an 80 year-old house with spiral balances in the windows. They are in bad shape. Some are missing parts or missing altogether. I am sending photos, but I'll bet you have nothing like these in stock, so I'm hoping you can provide all new equipment to install in my sash channels. The sash channels are 5/8 inch square and 29 3/4 inches long. The spiral balance's shaft is 27 3/4 inches long and ca. 3/8 inches in diameter. The bottom retainer is 5/8x5/8x1/2. the Bottom Detail shows how the retainer fits around the shaft and is attached to the channel with a single screw. The Top Detail shows the two attachment tabs. The leftmost one is screwed into the channel before the balance is laid into the channel. It is 3 x 7/16. The smaller one attaches to the channel above the sash. It is 2 1/2 x 5/8.
Let me know if you need any further information!
Many thanks,

George