I have no clue what the problem is with Ruger's ancient take down system. As a sub-10 year old in the 1950's, I picked potatoes at 5 cents a bushel until I collected $37.50. The local hardware ordered me in a Ruger RST-6. The Ruger Standard Model 6" .22LR of the 1950's.
I actually read the instructions.
The first day, I sat behind my house and burned a brick of Rem22LRHS 40grain ammo of the era that may not yet have been called Golden Bullets, but I had a case of them copper plated as they are today. Earned the case at 5 cents a bushel.
The gun was dirty.
It was cleaned and re-assembled that day by a 8 or 9 year old.
The only "trick" to the process is to actually look at the tang of the hammer strut and SEE IT ENTER the little groovee in the top of the hammer spring assembly as you close up the system. If you actually watch it close up in the right spot, there is never any error. But then again, I could read fairly early even in Bubba Land.
To get the receiver off the frame, wack the end of the barrel with a soft shoe. To put it back on, wack the back of the receiver with the same soft shoe. Or as an adult, use a rubber mallet with no metal filings in it.
The new Mk.IV falling apart as you open it is for sandbox vets. Guns that fall apart are not really needed if you understand the system of the older ones.