I would willingly look up John Charles Macdonald in the 1901 census if I knew which John Charles Macdonald you are looking for.
I've already posted the index listings of all the marriages of John Charles M(a)cdonalds from the Scotland's People web site. There are 13 of them. No-one is going to spend their own credits looking up 13 marriages for you, even though each lookup only costs a fraction of the cost of a cup of coffee. They might perhaps be generous enough to look up one if they knew what the wife's surname was.
But if your John Charles Macdonald was the one born in Penzance and died in Wales, it would be a waste of money for you, or any helpful person, to look up any of them.
And by the way, there is no record of a birth of a Charles M*cdonald or a John Charles M*cdonald in Greenock East, Greenock West, Port Glasgow or anywhere else in Renfrewshire in 1882. Which means that the birth in the tree not only isn't the right person, it doesn't exist at all.