Sorry, it's true, there are no off-the-shelf replacement Patridge sights for Ruger single actions except
the one Ruger factory sight for the 22 Auto I linked to below.
Or the custom smiths who have had to produce their own. And as you probably found out, they are not cheap and there's a long wait time.
Otherwise it will take some creativity.The original sight must be unsoldered and the new sight screwed on or soldered on. So whatever you do will have to be a custom of some sort. But there are much cheaper ways to go. If it's not something you want to tackle yourself, it will have to involve a gunsmith, but not one of the custom smiths.
Your stainless is the easiest. You or your gunsmith can drive out the pin. Use one of many available blade blanks. Then blue it and mount with the pin. See links below for several blade blanks available.
The same thing applies to the blue gun but as I mentioned above, the original blue base will need a milled slot to match the stainless sight base; also not difficult for any gunsmith. A blade as above can used and pinned in place as well. The benefit of using the original sight base that's soldered on the gun already, is that you won't need to remove and re-blue the barrel.
This is what I found from googling:
Here's the Ruger factory Patridge sight for $9 .420" high that screws on. You could have your original sight base unsoldered and screw this on. Or your original base milled flat as well as the bottom of this one, and screw it on and you won't have to re-blue.
http://www.brownells.com/handgun-parts/sights/front-sights/sight-front-prod12322.aspx
Here's several Patridge blade blanks around or under $10 from Brownells that with a little reshaping of the bottom can be pinned in. Some have a dovetailed base. On your blue gun, just cut off the original blade and dovetail one into your original base:
http://www.brownells.com/handgun-parts/sights/front-sights/1911-wide-tennon-front-sight-prod44424.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/1911-auto-front-sight-prod8842.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/strong-front-sight-prod31828.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/1911-auto-ramped-dovetail-front-sight-prod26349.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/dovetail-mount-front-sight-prod9685.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/sight-front-243-black-patridge-prod14988.aspx
http://www.brownells.com/handgun-parts/sights/front-sights/sight-front-prod7358.aspx
Hope this helps,