See the link below for instructions on how to make your own imitation Handi-Writer pencil grip device. My son with classic autism used a homemade device made of a large women's headband and a small plastic soldier substituted for the dolphin charm that comes with the commercially made device.
Here is a link to a sight where you can purchase a weighted glove. My older son sometimes used a weighted glove during handwriting practice and had some benefit from it.:
