The SL-710A drive can be found in some very inexpensive dvd players. My Resolution Audio Opus 21 also uses that drive. When mine was having trouble I did a lot of research trying to find the drive at a reasonable price. My research also showed that drive to be a fairly problematic drive.
Ended up buying what was claimed to be an almost new dvd player on ebay that had that drive in it. Sure enough for about $30 I had a like new transport ready for install from ebay.
Unfortunately, I threw the case away or I'd take a look and get you the model number. Google is your friend if you decide on that route.
As for cleaning the lens, I'd take a qtip with a light alcohol dip and swipe it. Be CAREFUL though as it is delicate. You can also get a can of compressed air and blow GENTLY at the lens. Good luck.