Hello Chris Welcome to Rootschat
From England to Africa and back,how wonderfull.I will help you all i can but trying to find a burial without a year or near even for me

takes a long time going through the films.BUT, you maybe in luck, a few months ago i found a new source whereby i can look up burial without knowing the year, and religion, not every single burial is on the records but it will save me heaps of time if it is

. Tell you mum not to worry if there are buried in Rake lane i will do my best to find them you never know she might remember something she thinks is relevant ,but important to us.I went through all deaths on the G.R.O and like you didn't find them. if they died in England they should be on the G.R.O. I will go through them again though because it was late and i was a bit cross eyed

I had wondered if they might have been cremated,but Landican didn't open till the 1930's.The only reference i could find for Frederick was his birth in Cumbria.Nothing after that ,i found these deaths district wallasey reg wirral on the U.K B.M.D. If these names are any connection to you maybe we can start there This doesn't mean they are in rake lane though.
1887 Alice Woodburn age 75
1896 Robert Barber Woodburn age 68
1900 William James Woodburn age 75.
For William James (if yours) i will have a look on the newspaper films in the 1900 editions.I might be lucky and find an article which gives lots of information.Even an small entry in the orbit column might help,they don't give much info though. Anyway i will see what i can put together for you,i have a few weeks before the your cousins visit. So that gives me plenty of time for trips to the library.
Best wishes Celia