I have a signed Alfred deBreanski pencil drawing - not oil painting-
of a meadow/tree/cottage( not a usual Scottish Highland scene )
24"/12" framed. Is it worth selling?

Probably information you already have.... but maybe not! 

It looks as if DeBreanski Junior's landscapes are highly valued and
copies are widely sold also online. In ths ite below, three of his
works are sold for quite a bit of money (up to 600 USD) for a framed
offset lithography (therefore not an original work).

http://www.artinaclick.com/search/results.asp?fk_artist=6330&CallPage=frameit

An original painting of Alfread DeBreanski Senior instead sells for a
lot more, and the one below is currently on sale for 3495 British
Pounds.

http://www.millingtonadams.com/index/index_1309.htm

Now, it would be importnat to figure out which one of the two is your
skecth by and possibly the date it was made.

This site says that deBreanski Sr. works have sold well at auctions
and provide more deatils about him.

I cannot give an estimate of this sketch, but I would say that it
would sell well on the Art Market, especially if proven authentic
(that is you will have to submit it to an expert for an appraisal) and
never seen before, as it would be the case if it were in your family
for a long time. It seems that the works of both the DeBreanski have a
faithful group of followers. Good luck with the sale!

Other sites who may have sold his work in th past are:

http://www.lochgallery.com/artist.php?artistID=82

http://www.austingalleries.com/artist_bio.asp?ID=187