I rebuilt both front seats in my 84 & 85 300D. I posted photos in another post. I also unbolted the bottom from top, and didn't fool with the top in both cars. My main additions are that I tied the top wires together with either "rebar tie wire" or a net of 1/4" poly rope, covered w/ spiked carpet runner, then a layer of thick rubber foam (garage shelf liner at 99c Store). The 85 had horsehair, which was more degraded, so covered the top w/ thick burlap. I hog-ringed the carpet runner and burlap to the steel frame. I glued the felt runners back to the seat covers. I repair broken springs by inserting the ends into 1/4" copper tubing w/ epoxy and crimping. I spent more time freeing up and lubing the seat tracks. I used harsh-weather bicycle chain lube since it is supposed to stay put and handle dirt. For the finale, I use sheepskin covers which feel fantastic.