I recently bought an old set from early 60's. The bricks were in poor condition but at least they gave me some inspiration. For most of these creations there was an original Lego model which I kind of "replicated". Or at least the pictures of old sets were studied and used for motivation and inspiration.
Here's the first one, only vintage bricks were used.
Bottom:
And here you can see the poor condition of those vintage bricks. (They were partially glued to make at least some strenght):
And the original model 310:
The second one, "A movie theatre" was also made of vintage bricks from the same lot.
I really like "the old wibe" you can feel in this building. Here's the backside (sidenote: the 2x16's here are newer):
Those were the first ones and pretty much the only ones where I used the very old bricks. Those poor old bricks were almost impossible to build anything.
I managed to buy another (actually quite a big) lot of old seventies bricks and this Shell station/garage was one of the first creations which I build of them. There's still old feeling in it and vintage bricks were utilized quite a lot, even though you can consider this as a "MOC".
Bottom:
The one on the right is based on existing set 648 (see picture below) but also on my own design with rounded corners. I really like those rounded corners, they are giving sort of art decoish style. One on the left was made of old and newer bricks on a vintage 4x8 plate.
And the last for now is the truck 688:
Hope you enjoyed. Thanks.