I know this is a little off-topic, but ya’ll are just so darned smart. My teacher gave me this sketcbook earlier today… I really like it and I’d like to buy a bigger one like it. The only problem is I don’t know the brand name.
I’d be really surprised if this is still being produced or sold. Judging from the lettering and especially the illustration, my WAG is that it’s really old, probably from the '30s or '40s. But I’d guess your local art supply store would have something similar.
Take it with you to an art supply store - not a Michael’s or other such ilk - but a genuine art supply store, perhaps near a college.
The sketchbook you scanned looks old - the style of illustration, lettering, and the yellowing of the cover. Most likely, it was made a long, long time ago. However, you should be able to find something of a satisfactory size with similar paper.
Is it used at all? You know it could actually be quite valuable if it is still completely blank. Quite aside from honest buyers, forgers of historical documents are always on the lookout for old, blank paper. OK, it’s not ancient, but it might be old enough for, say, an ersatz letter from Winston Churchill.