The rear engine hanger wouldn't really help much. To do a custom fabrication like your wanting to do; the bike really should be in person to physically make the alterations. Or buy a pre made kit for your specific scoot, which has all the parts and dimensions ready to go. Even those kits tend to need slight modifications and tweaking to fit and go together properly. Basically all those kits for "stretch" essentially are, are brackets to extend the swing arm, and a relocation or addition of a "riser" for the rear shock bracket. The rest is mostly cosmetic. This is a simplified and basic explanation but more or less checks all the boxes.
