I have an SP1 carbine bought in the 80’s. I think it is all original. Back in the day, I shot it and it was a great gun for my kids when they were young. It is very lightweight. I am thinking of selling it, but not sure of the value. If memory serves, the serial number indicates it was made in 1981.
Thanks, Steve
1978 according to Colt’s serial number search. Value? Private sale: $1,500 - $2300 depending on condition.
Thank you. I am trying to add a few more photos, but the site doesn’t allow it. I am sure I am doing something wrong.
Hard to say. In one respect the Colt retro reissues have driven down prices and demand for original SP1s, but at the same time created interest and demand. Best way to track actual values is find similar model in similar condition on GB that are actually selling.
I will say this, make SURE you want to sell. You won’t be able to buy one in the same condition for about the same price once you let it go and it’s a handy little carbine. Maybe your kids, kids will want it someday.
Thank you for the thoughts. The gun hasn’t been out of the safe in at least 20 years. I have plenty of other “guns” that my grand kids shoot. Back in the day it was the smallest light weight gun I had for my kids. Frankly, I forgot about this gun. This is what happens when you empty a safe to rearrange it. 
I found a bunch of other guns I am going to sell. The one gun that I bought, new in the box in 1978, is my SP1 rifle will never be sold.
GRA, I will send you a PM.
Cheers, Steve
I love my SP1, I would never part with it
Would be hard to compare a US market to Switzerland prices.