I'd appreciate it! My main save, my Crystal version, is ID # 64818. My second save, Silver, is ID # 41962. Could you also check my friends' ID numbers? I think one of them in particular is the one that's given my other friend and myself the SNES and the Surfing Pikachu, so I'd like to confirm. The one in question giving us those items is ID # 37613. I don't have the ID number of my other friend at the moment; I might edit it in later.
Also, just mere minutes before making this post, I Mystery Gifted on GBC and my Silver version received a Pink Bed!! I received on Crystal two days prior. I even have pictures to show both were received on the same two systems and same two cartridges, and not Stadium 2. I've been getting some good luck ever since my friend let me borrow his GBC so I could do more Mystery Gifting. That second GBC also happens to be pink. Coincidence? Yeah, but it's still weird. It might a similar oddity to the Magikarp one you mentioned before.
Before seeing this thread, I assumed the information I saw on Serebii was vaguely true, but I guess not. Their stuff from the first four gens tends to be less accurate. Still, all items were tiered into 5%s, 1%s, 0.2%, and 0.1%s. Bulbapedia also tiers the items the same way, but without showing the percents, since I'm guessing those are bogus if receiving the supposed 0.1% Surfing Pikachu Doll on my save and a friend's save is anything to go off of. If what you said about the 8 commons, 4 uncommons, and 2 rares is true, that might explain the drought I've had. But it's still strange that my Crystal save has 14 of the 16 commons, while my Silver has the two it's missing. It's not like each version would have the exact 8 that the other didn't have. It seems likely that my friend was the one giving me Magikarp and the SNES...I guess I just got lucky in the 20-ish times I've Mystery Gifted my friends. Also, I'm guessing the very rare tier of Surfing Pikachu and Big Lapras can only give one per save?