I've been on the lookout for alternatives to an entire light housing, my HS didn't come with a topper at all (I'll kill ddstoys next time I see him, I swear
;)) but most of the guts were intact. Wound up buying a 24VAC-12VDC converter and a 12VDC rotating light from dx.com. It's not perfect, but it does the job nicely enough!
Here's a video I took of the attract mode after I added another little modification underneath the cab :)
That CD spindle lid looks eerily close to the original though. Good thinking!