Having gone through different spring ratings on classic cars, and the headaches fitting non genuine / aftermarket brings, and more appropriately on here, fitting non VX rear springs (self levelling in my case) which can result in a Santa Pod lookalike dragster syndrome as many aftermarket suppliers list 'one spring fits all' malarky .......why did you want to fit new front springs in the first place? I appreciate that you may have had the struts dismantled for other work, but were you of the opinion that your front springs were shot at? If you were happy with their performance, they weren't excessively rusted (which I doubt as you mentioned the brown spots), or the ride height was lower than original because of weak springs, I personally would refit the originals, or replace with genuine new originals (which I appreciate maybe like looking for the proverbial rocking horse s**t).
No doubt this will bring the usual comments, but relative to suspension springs, I am a firm believer of fitting genuine / originals wherever possible to maintain the correct ride height.
I'd be tempted to refit the originals if there was no obvious problem with them.