On this site they’re labeled:  
Vinyl scratch: record scrape(its right up there)  
Spitfire: firestorm  
Cheerilee: jubilance

Vinyl would be Record Scratch  
Spitfire is Hurricane and  
Cheerily has always been Joyful in my mind.

For Cheerilee, I’ve always just like Cheerilou.  
Vinyl, Record Spinner  
and as Spitfire was obviously a fighter aircraft, I like ‘Hurricane’ or ‘Bomber’.

Vinny. VINNY.

Vinyl = Record Scrape
 
SpitFire = I agree with other background pony on FireBall
 
Cheerilee = Cherryloo

DJ COL7 is the only thing I can think of.

Vinyl Scratch => Cross-Fade (Sticking with the turntable theme)  
Spitfire => Corsair or Lockheed (WW2 fighter theme)  
Cheerilee => Merrimac (Because I like the name)

Vinyl Scratch => Dead Mouse

@Background Pony - Wouldn’t naming a pony Mustang be like naming a kid Guy? I see what you’re doing but it’s kinda like unintentional hilarity XD. (Laughin’ with ya, not at ya pal.)
 
Anywho:
 
Vinyl Scratch could be- Dub Step, Record Spin, Mix Jam, Mix Tape
 
Spitfire could be- Fireball, Nighthawk, Amazon
 
Cherrilee could be- Smiley, Merrimac (as suggested by dramatic_spoon.), Happilee.  
I really don’t have much for Cheerilee. Wish I did.
 
Welp, there’s my two cents.

I used Merrimac for Cheerilee.
 
don’t really care about the others.

Spitfire could be Mustang. Both WW2 allied aircraft.

Echoing the “Vinyl and Spitfire are neutral names and don’t need to change” position.
 
Cheerilee is tricky.

Vinyl Break, Jollilee, and…Fireballs? :D

C.D. Skip  
Supermarine  
Cheerio

@PwnyPony  
Cheryl Lee. I’m honestly stunned at myself for never noticing…

@PaskaNaakka
 
No, that’s the real name of Spitfire’s rival, the Roan Baroness.

Spitfire -> Messerschmitt

@WatermelonRat  
This might be rude but.  
What is her name?

As always, pony names aren’t gendered, but the first two are already as butch as they’re going to get. The third can be shortened to Lee as a nickname.

Holy shit guys, I just realized that my mom’s name is almost identical to “Cheerilee.” She’s even a teacher.

Vinyl Scratch and Spitfire are both perfectly good gender-neutral names that don’t really need distaff counterparting.
 
“Record Scrape” is awful. If you must give the DJ a 63 name, go with Bass Wave or something.

We can get rid of the other one.

Cheerille- has one, it’s Sunny Smiles.
 
Spitfire- Blaze… something
 
Vinyl- Turn Table

Vinyl Scratch  
Spitfire  
Cheery Lee