If the Mario universe were in the same time span as ours, and Toadsworth is 62 now, that would suggest he was ~42 when SMB took place. Now, in that 20-year span, NONE of the characters have gotten any older looking. Apparently they DO age (in appearance), however, since you can see...well, look at SMW2 and PiT. They're all obviously younger. So, if Mario is middle aged now, like, say, 43, 20 years ago he'd've been 23, which works, but if you go 20 years earlier, when he'd be a toddler, that'd make Toadsworth ~22, which doesn't fit at ALL; I don't know many 22-year-olds who are very fatherly and overprotective and paranoid, as he is with Baby Peach. Actually, I don't know any who are. XD
Also, this theory is flawed in considering Peach. PiT shows she's a baby when the Bros. are toddlers, meaning she's not much younger than them. If the Bros. are, say, 43 now, that'd make her about 41. I don't know about you, but I don't see HOW she could pass as 41. She looks closer 16 than she does 41, I'd say. Since she and the Bros. are about the same age, and considering their appearances, putting them in their 20s to early 30s makes the most sense.
Now, one could argue that their time goes by as ours does, but they simply remain young looking for a long time, and not look their ages at all. Like, say, they age twice as slow as us. However, this cannot be the case since Toadsworth has a specific age (as do other characters)--62, if I remember right. He looks his age. If they aged slower but time went by as ours does, going by how he'd look, his age would be something like 120.
And again, the Bros. and Toadsworth have GOT to be way more than 20 years apart.