Help Me Id These Springs?

Hello, I'm looking for some help. I have a set of springs that came with my 91 LX 5.0 hatch. They sit close to a 3" drop, the car corners like its on rails, but rides very harsh.
They are red. Fronts sit 12" high free-standing. The only mark on them is "SP2100F" printed very small at the bottom of the spring. I've been looking and calling and googling for a week, and no one knows what these are. Search results get me parts for gas equipment in the UK, with ONE automotive link to American Muscles lowering spring page. But not to a specific company or spring. I called, they don't know what it is either.
I've verified that they are NOT Eibach, BMR, H&R, SR. I will continue to call, but would appreciate any help. I would like to unload these springs in favor of some Eibach Pros, or even stockers. Thanks!

I think I found them. There is an ad on eBay, even though they are for a similar model year F Body, they have SP3100F printed on them exactly the way my number is. They are being sold by some eBay store under the brand name LOTEK (why would you name your company that?). I believe these springs are being made by the thousands overseas (read: China) with ty quality and sold by these two-bit eBay stores under different names-if they even use a name. For instance, I messaged several of the sellers asking for info on the springs they were selling, and only one responded. This was his response:

"These springs are manufactured over seas. I do not have a name for them. I also only have the specs listed on the product listing through eBay. I do not have any measurements or spring rates.

Best regards,
OPTION RACING"

So he doesn't even know what the hell he's selling! I believe his springs were the same as mine. The only specs listed were how much they would lower the car. My car was sitting on the bump stops!

He was selling these for around $100, and in my search I have found a lot of people asking about deals like this on eBay. They are looking to lower their cars cheap, and they are not thinking about important things like spring rates, let alone sagging. So I will say again:

BEWARE OF DEALS THAT SOUND TOO GOOD TO BE TRUE; THEY PROBABLY ARE, and YOU ALMOST ALWAYS GET WHAT YOU PAY FOR!!

Now I have to find the money to come up with the money for real springs; like a set of Eibach Pros. Hell, you can't even nab a set of stock springs for less than $100.

Thanks everyone who looked.