Paralever or monolever? It makes a difference due to the different headstocks.
Risers for paralever bikes are available from Migsel.com
Monolever risers are a whole other debate, not easy to do without significant work due to the flimsy plate across the top of the forks. Do a search for plenty of chat on this topic.
Try the Moto Technique risers. I fitted a set to Jill's 100gs 1" up & 1 1/4 back (others available) I got them direct from the States, but they are available from Sportouring.com
Try the Moto Technique risers. I fitted a set to Jill's 100gs 1" up & 1 1/4 back (others available) I got them direct from the States, but they are available from Sportouring.com