What you need is a street titleable FRAME. The rest of the components are optional. The older the FRAME, the easier it is to get the tags.
All of my old two strokes are enduro models, which were street licensable in their day. So long as they meet the requirements of the year they were manufactured, generally it is fine. You can take a bunch of MX components and graft them into an enduro frame and it is just fine. The newer the bike the more difficult, as more requirements were added, and in the last couple of years, EPA got involved.