I challenge you Google-nauts to find me a famous image.
It is a figure of a knight, carved onto a sarcophogus lid. I think it may be in the St-Martin-in-the-Fields church. My friend’s mother went to England and did a rubbing of it. Apparently it’s a big tourist thing.
I know it is a simple 2d image, just etched. Otherwise doing a rubbing would be … challenging.
I noticed your post yesterday and noticed also that no one replied.
Fact is that you can find those bas-relief in almost any church in england; so without further hints it might be impossible to find anything.
One famous sarcophagus is the one of prince Edward (“The Black Prince”) in Canterbury Cathedral:
In this case it’s not a bas-relief but a brass statue. I doubt your mother’s friend could have done a rubbing because it’s behind bars so probably it’s not what you’re looking for.
Here’s a few to get you started:
http://medievalwriting.50megs.com/exercises/stafford/stafford.htm
http://www.mbs-brasses.co.uk/brasses_slabs.htm
http://www.britishbrassrubbings.com/brassindex.htm
http://www.medievalgenealogy.org.uk/sources/brasses1.shtml
Some search ideas if you need to go further:
Funerary Brass
Monumental Brass
Brass Rubbing
Phil