1) Hold the phone:
BEFORE doing anything locate an ownership for that (if you don't have one, you don't say), sometimes up your way they can be easy/hard to get, depends more on the time of the month, than anything else I can figure. Now you can proceed.
2) You are missing enough stuff, that locating a second one for parts is a practical idea, a non runner should cost around $50 in your neck of the woods.
3) Turn signals are a bitch. Your (any) Jawa does 6V at a very small amount of current. When Java added turn signals they also added a battery (or a set of ni-cad batteries, a rectifier, and a regulator) Anything used you are going to buy will be shot, and it could run you $50 to get something working, you do not "need" on a pre-78 moped. I have a shot set-up here that you can have for shipping (bad ni-cads), I run without.
4) Brakes? (I have 12,000 km on the originals and they are hardly worn)
5) Your pedal chain needs an adjuster.