Double Skinned Rear Quarter- Does it have drain holes?

[Ice White Socks 0]

The reason I ask is cos I had a dent removed on the arch flare a few months ago- and the guy drilled a 4mm hole in the inner arch to get to the back of it- came out perfect :)

 

I need to get it covered before winter. Was thinking about just cutting back the underseal- aralditing a penny over the hole and then sealing over the top (unless anyones got any better thoughts...)

 

Whilst I honestly don't think any waters got in cos the underseal feels like its closed over the hole- I aint taking the chance of sealing a bit of water into the rear quarter only for it to fall to bits on me in a couple of years. Is there a drain hole in those rear quarters or do I need to think of another way to make sure its dry inside :(