Look at the listing number of the one on GunsAmerica - It's been listed for a few months I have been watching to see if it sells.
Here's a picture of one that was listed on GunBroker 12/29/2003 - the picture isn't very good but it does show checkering that was supposed to be original, price was $1000 with $1,120 buy it now - don't know if it sold and there was no serial listed. This would be the 430.
Here are some more pictures that show the end of the breech block, it is milled to clear the hammer when fully opened but has a lot of locking area on the right side. Also a picture of the repair on my stock which shows the open area needed for clearance. Also a picture of the butt plate which is the only type I have seen on a High Power and have never seen a similar one on any other Stevens.