Two options.
    I bought a similar light in plastic with led from 12 Volt Planet Ltd ,price including vat and delivery £38.32.
    Product code P01133
    Part number XS9410MS
    Fitted well as dims all but identical and it swivels all ways.
    I guess delivery cost would the same for two.
    Secondly I have sourced some 15 mm dia rocker swithes off ebay for £2.99 each.
    I will let you know how it goes when I have fitted one as I will have to file down the lugs on the light that hold the black rocker .
    Watch this space
    ” WISH “