The only Tomos I've had that didnt get over 40mph was a stockish Tomos A3. One of them was a Streetmate with modded air-box, bi-turbo pipe, smaller rear sprocket, oil injection intact, and re-tuned stock carburetor and it topped out at 45mph on flat ground.
37mph with all of OPs parts tells me its likely not tuned properly, restrictive air filter, and/or geared too low.
your picture doesn't have all the mods you listed. take new pictures. (edited)