Mine likes the Crosmans too. Your groups look great and they will tighten up as things break in.
The limbsaver is a great idea. It makes the rifle much easier to shoot.
The rifles jump forward a lot. Off your shoulder and into your offhand. I pull into my shoulder a bit with my offhand and relax my trigger hand. It makes the gun cycle straight back and forth (with the help of the squishy pad) and reduces the group size a lot. Remember that offhand tension when mounting the rifle and it drops them in the same spot every time.
Shooting off a bag or rest is iffy IMHO. The gun can only jump "up" and I find my groups open up a bit and hit 1"+ higher than when the gun is held.
My best and most consistent groups are holding the rifle while sitting with my elbows on my knees. It eliminates any recoil movement and greatly improves your pattern and consistency. The POI is the same as offhand or kneeling. When the rifle is zeroed off a bag or rest it always hits 1"+ lower when shooting in a natural position.
Those recoil pin holes are tiny. I considered making a pin but thought it might shear it off. And it's going to be difficult to get the offset. Most mounts aren't going to center exactly over the holes. I think the hole in the tube should be drilled out large enough for a standard pin. When I take mine apart that's what will happen.
I mounted a 40mm scope with medium Sportsmatch rings without a recoil pin and it walked back in 100 shots. The 34mm scope on low rings held just fine for 1000 shots. A smaller scope on low rings has less inertia and seems to hold much better. If I mount a scope on it again it will be a light 32mm on low mounts.
I shoot mine mostly open sights. I think as hard as it kicks forward a scope will always be trouble without a fat hole in the receiver that will accept a recoil pin.