Antique Architectural Drawing Instruments in Case

I know absolutely nothing about drawing instruments - so I will describe them in the best way I can.

I would imagine they are complete, as there are no gaps in the case, and generally they look in good condition. There are still some pencil leads in the bone case.

In the lid there is a drop-down part which reveals where the blotting paper is kept (well, thats whats in it now) but I suppose perhaps some drawings were kept there.

The case itself is not in good condition, but the catch for locking it is there, which I hope you can see from the photo.

I would think the age is about circa 1910.