u/Holiday-Release

I have a used motor scooter circa 2016. The title has never been signed since its initial sale from a dealer (completely blank), no bill of sale, & successful VIN check.
DMV just turns me away without a bill of sale.
I purchased in a private sale, seller said only title is needed for registration.
I’m now contemplating just writing title and bill of sale to myself since there’s no paper trail of this thing.
Or taking seller to small claims court to at-least get money back.
Advice would be great.