It sounds like you are making good progress and have the dedication and tools to succeed. David Riccardo is a top engraver and designer so you received instruction from one who knows what he is doing.
Since you will eventually be working on car and MC parts I would suggest you concentrate on styles of ornament that are best adapted to the large surfaces you will be working on. Some of the scroll styles are best adapted to jewelry, guns, and knives.
Best wishes, let us know how you are doing from time to time.
Roger