Just had a look at MGN (9), which deals with revalidation, and I am afraid it does not look so promising, unless you have heard different from the MCA.
Looks like you need to be signed on to an ocean going vessel over 24 M in length for 12 months in the preceding 5 years to revalidate.
Or you can sail as OOW for 3 months as supernumary on a vessel, during which time you will need to update your professional knowledge.
If you are an ocean going vessel, then either of the above will get you a revalidation of your radio licence.
Failing all of the above it looks like back to college to do a revalidation course (which might be the easiest option, depanding on your circumstances), however I do not know how long, or the cost of the course is.
It also lists a number of occupations which are exempt from the sea time qualifications, but I do not know if you would fall under any of those.
There is a final route, and that would be to apply to the MCA citing your occupation as an accepted one, and they may accept this, and revalidate your licence on that basis.
Good luck and hope you get a positive response from them!