1970's, or earlier, then open sights are fine.
From the start of Airgun World 1078 then scopes and air rifles took off in a big way.
Some 80's rifle were still iron sight biased, BSA Airsporters are such. Most had sporter stocks so cheek combs set for open flat sights.
Jap scopes were the right price for putting on air rifles. Low magnification to start, with the x4 most commonly fitted. Soon 3-9x40 were taken up, and by 1986 anything went including big 56 objectives. Late 80's anything went including high end scopes.
Here are some examples of well matched, best looking combo's that I've managed over the years:
http://i820.photobucket.com/albums/z...e/IMGP6760.jpg
http://i820.photobucket.com/albums/z...e/IMGP6778.jpg
http://i820.photobucket.com/albums/z...IMGP6766_1.jpg
http://i820.photobucket.com/albums/z...e/IMGP6797.jpg
http://i820.photobucket.com/albums/z...e/IMGP6733.jpg
http://i820.photobucket.com/albums/z...e/IMGP6138.jpg
http://i820.photobucket.com/albums/z...IMG_3971_2.jpg
http://i820.photobucket.com/albums/z...e/IMG_4087.jpg
Get them looking just right is quite difficult, but fantastic when you do.
Many rifles just don't look comfortable scoped, especially the older designs:
http://i820.photobucket.com/albums/z...e/IMG_3593.jpg
http://i820.photobucket.com/albums/z...e/IMG_4094.jpg
Scope mounts and their look and finish does make a difference. Its a nightmare trying to match the quality, look and overall combination to look "correct". When poor chosen parts a good looking rifle can just look all wrong. When matched right its a real plus and they usually handle and shoot better for it.
Anyway, its one of my passions to get my rifles looking right. Its really not easy, and a hobby in itself. Buying a rifle, even mint rifle, is the easy bit.