to 2404: 1+2 = 3+4

The first and second letters of the unclued lights are the same as the third and fourth ones. All the solutions are words or one phrase eight letters long. ARARAT at 32 Down matches the pattern but is only six-letters in length and had to be highlighted.
 
First prize D. Thorpe, Totternhoe, Bedfordshire
Runners-up John Honey, Brentford, Middlesex; Brian Le Marquer, Horndean, Hants