Certainly you won't buy a purpose made cabinet, sorting the flue out would also be a issue.
Grants are decent boilers but at 14 years old depending on how it's been installed it's probably in the latter part of its life.
We replace 2/3 oil boilers a week, there are odd real oldies amongst them but most are 15 to 20 years old.
Have taken out some that start with a W leaking at 4 years old.