blown engine

hi everyone, im new here and know nothing about cars and would love some help, i have a june 98 jap import mx5 1.8 with 6 speed mark2. the radiator emptyed from a big leak and the engine got so hot the leads melted on the plugs. the car wont start by the key but will start on a tow when it does it boils off the water in the radiator, so do i need a new engine or the head skimmed, if i need a new engine which one is mine im not sure what the engine code is,i have taken a few photos and put them on bebo cause i dont know how to put them here i but here is all the info i have vin is nb8c104249, on a sticker on the door there is info http://www.bebo.com/PhotoAlbumBig.jsp?M ... 0007846600
on the airbox and on the fan behind the radiator is bp4w but on the black round thing "sorry" under the bonnet opp the steering wheel is 833-04291 8514 in the reg cert it says 942401? which is the vin backwards, so can anyone tell what to do and where to get it done , thank you in advance for your time and help, p.s i live in bundoran county donegal
on the airbox and on the fan behind the radiator is bp4w but on the black round thing "sorry" under the bonnet opp the steering wheel is 833-04291 8514 in the reg cert it says 942401? which is the vin backwards, so can anyone tell what to do and where to get it done , thank you in advance for your time and help, p.s i live in bundoran county donegal