I have done some more digging around and I found out that only one substitution is being made for each entry in the table.
For example:
For Cemetary Road, there are two possible substitutions in the locator style, on eofr cemetary and one for Road. In this case the cemetary substitution works but not the Road substitution. For this one, I cannot get a match when using 'Cemetary rd'.
For Larter Road, only one possible substitution exists, Road. For this one, I can use 'Larter rd' and get a match.
This probably has something to do with the fact that I am using a single line entry.
Phil