Mmm I'm not 100% sure that is your great grandfather in Eastwood Old Cemetery, but I'm willing to be proved wrong

I'm sure Eastwood cemetery would have been under Renfrewshire, quite a few miles away from the Glasgow Royal Infirmary where he died and Dennistoun where he resided.
You're right in the fact there is a James Henderson listed in 'findagrave' who died 1901 and buried Eastwood Old Cemetery, I can't see another listed.
In 'Billion Graves' there is also a James Henderson listed who died 1901 and buried Eastwood Old Cemetery but he died 12th Sept 1901 and was killed in the Boer War.
Again, there is only one James listed.