I think from the two pictures provided it's not too difficult to envisage the parts for a launcher.
The first picture shows a launcher which basically consists of a tripod and attached to that is a piece of u-shaped channel to take the rocket. The channel has a vertical, moveable rod from it to the ground and the angle of the rod to the ground determines the angle of elevation of the channel.
The second ladder type is basically a step ladder with two channels attached, one either side, at the top of the ladder side. (In fact, it looks as if each channel can hold two rockets.) The angle of the step side (and, therefore, the angle of elevation) can be adjusted by moving the non-step part of the ladder in or out.
Overall, pretty simple, even crude, devices. Not, it might be said, exactly rocket science!