[kovidgoyal]

There are two alternative approaches you can take

1) Get the webpage and search for the cover URL in it

2) Try alternative URLs

Both require some programming

I'll outline 2

from datetime import datetime, timedelta

t = datetime.utcnow()
while True:
    url = t.strftime('http://whatever/%Y/%m%d_large.jpg')
    try:
         self.browser.open(url)
         return url
    except:
          t = t - timedelta(days=1)