How to spot a first pressing

I've found some old LPs in the attic, not all in the best condition. I've been told old classical LP's can be worth selling on ebay. One is an HMV with a white and gold label, is this a first pressing? Another is red and grey (10"), what about this?
The white and gold one is called Operatic Duets, and has a few scratches, but would be very playable, anyone any specualtion to it's value? Is there a site or resource I can be steered towards to answer these label questions?
Thanks
Harry

 

Classical LP's are practically worthless unless in unmarked condition. I certainly wouldn't buy anything unless it was in excellent condition. There's a very useful label guide here:
http://www.pinkfishmedia.net/forum/showthread.php?t=8266

A little bit here as well:
http://www.classical-lps.co.uk/guide.htm

The best advice I can give you is to google the number on the sleeve SXL____ or ASD_____ .You'll probably find that someone else is selling the record. If would have to be outstandingly rare though for someone to buy anything marked for good money.

Surprisingly enough 10" and mono's are not the best money earners unless they are something really special. Again google the number.
If yours is ASD 2382 I've found an excellent copy for £8 here:
http://www.spiralclassics.co.uk/catalog/lista.html
It's listed as excellent with a light non sounding mark.

There isn't a fortune to made from classical records. The Cream and Gold ASD's, Wide-Band Decca's and Early Columbia's are most collectable. Original Mercury Living Presence and RCA Living Stereo's are also worth money, particularly if they've come from America, many say the USA pressings are preferable.

Good luck with them