There are 3 things I would buy for your collection. First I would buy a semi-auto .22 for plinking and for small varmint control. That Sako is super nice but if you're taking on a garbage dump full of rats trust me you'll want a semi-auto. My choice has always been a Marlin 60 for that purpose. They're dependable, accurate and inexpensive. Obviously Ruger 10/22's are also popular. IMO out of the box the 60 is a better rifle. But the Ruger can be made into a much better rifle with money to spend.
I'd also get a medium caliber, semi-auto rifle for protection in the worst of situations. Some even argue they are better than shotguns for home defense. I have an SKS and I love it but I bought it when they cost $100 and an AR was $1200 or more. I stocked up on ammo for that rifle or I'd probably switch to an AR. Both are nice weapons. The SKS is probably more reliable IMO but I'll no doubt catch flak for saying that.
I'd also get a long range hunting rifle. There are many calibers to choose from. A .30 caliber is probably the best choice with my vote going for the 30.06 but the .308 is also great. I don't know your situation but where I live they could come in handy. I'd buy a bolt action. Only people in wars generally need a semi-auto 30 caliber rifle.
I might also get (actually I did) a long range varmint rifle. Coyotes are a big problem in many places and if you have open space around wher eyou live i'd watch very closely for those pet killers. There are other nuisance animals if you live in the country on a farm. Ground hogs and p'dogs cause big problems. And feral pigs can be a huge problem. You may want to use the .30 caliber bolt rifle for that.
There are popular choices that people mention that I wouldn't bother with. For example I'm not a fan of lever guns. They were great in the 19th century. But this is the 21st century. Yes they kill many deer in the 20th century but a semi-auto is better in almost every way.
You already have some good weapons in that S&W 629-4. Only geniuses use that handgun. Did I tell you I have one?
The Ruger pistol is also a great choice but not as useful as some weapons like .22 rifles as an example. Your Sako is among the best rimfires you can own BTW.
You have about 3/4ths of the guns I looked for to complete my collection of guns as tools. Once I got all those I needed I started on guns that I like. Only you know if you need the guns I suggested but they are guns that fill a specific role for you. Maybe you need that role filled and maybe you don't.