If you need to carry out repairs on your Jawa Mustang then it is usually a good plan to have a Workshop Manual to use as a guide in case you want to know the best ways to strip off a particular part for example Exhaust and fit it again accordingly.
Jawa Mustang Workshop Manuals gives you detailed diagnostic info for the vehicle so if something is broken it can help you work out what the problem is and easy methods to make it better. You can then assess if this can be achieved on your own or if the job is simply too big you could book your Mustang into a decent friendly mechanic.
Jawa Mustang manual