I have a 1984 RV-3A, purchased with broken motor mount. The motor mount and gear legs are replaced together, as the gear legs are aligned and taper drilled in the field, you only get one shot. There have been a couple of threads here dealing with loose gear bolts, JB weld and other patches, but the best way to do it is replacement and it takes time. Do all your homework first.
I can tell you that the gear leg alignment is pretty straight forward, and important. Once you get it jacked up (in level flight attitude), if you take the wheels off, you have to ensure both axels are aligned parallel , and the measurement from fuse center line to axel , and from axel to center line at the tail wheel are pretty close. Mine were within 1/8". The angle of the axels to the ground will not be parallel with the airframe un-weighted.
As far as CN-1 and CN-2, I had that done on my plane. Yes you can look inside the inspection hole at the bell crank, but the best and most important check is to contact Vans. You CAN'T re-placard the airplane unless you contact Vans and document the changes. I had to get a builder number from them which corresponds to my serial number, They made some changes internally to update the Vans Registry to show me as the current owner so that you can receive service bulletins and other important info.
I had to order the "Kit" for CN-1 and CN-2 changes (less than $100) which is just a few sticks of angle aluminum, some sheet and a bunch of rivets. But it is important to order and receive the kit from Vans. There is not a lot of material, but it took us over 100 hours to remove the wings, drill out rivets to un-skin the bottoms, drill, rivet and install all the angle, lightening hole covers and other things. We had to fabricate several custom straps and braces as well.
Keep in mind that EVERY RV-3 is different...especially the early ones. They are all hand drilled by the builder, and mine had peculiarities that required consultation and supplemental drawings from Vans...don't worry, this was at no cost and they are VERY helpful. It is CRITICAL to inspect the wing attach bolts, spar carry over, and other structural elements while doing this if the goal is to do acro. There were some wing failures early on which were attributed mostly to poor build practices, but CN-1 and CN-2 were invoked to amend what was considered a "marginal" safety factor with the early spar construction.
All of this info can be gathered through this forum and from Vans, but having a starting point helps. I cant stress how important it is to document the entire process if you choose to take it on.
Best of luck to you.
My RV-3 is more fun on accident than your Cessna is on purpose