It may just be how I'm interpreting your statements and question, but I'm sensing two different approaches are on your mind. Getting clarity around your end goal will help you attain that goal.
You indicate you are a consultant with a methodology that works. At the same time, you indicate that the identified need is often a missing layer between business owner/CEO and front-line sales - the missing layer is a type of sales leader/manager.
If you wish to fill the missing layer, that sounds like you are wanting to become a VP of Sales or some similar role. In that case, you would approach your problem as you would approach a job hunt. (The "how" for this fills innumerable books, articles, etc.)
If, on the other hand, you want to focus on consulting, AND you are still focused on the missing layer, you'll have to figure out some way for that layer to be filled. Are you giving the CEO new skills, helping the CEO identify someone who can fill that role, or some other approach? By the way, if you assume you can partially fill that hole as a part-time leader, I'd suggest re-thinking it. Leadership, including sales leadership, requires a wholesale commitment to the team. So, someone still has to fill that role.
To continue on that consulting path, though, you've actually pinpointed your answers. Referrals and relationships are ideal for a consulting firm of one. Beyond that, since you're a sales consultant, be your primary client. Use your methodology to stir interest, create a pipeline, convert to clients, etc.
One last thought. The needle in a stack of needles is an apt description. There is a HUGE number of small/medium businesses out there without a sales leader. Do some market segmentation for yourself. Industry, geography, company size, etc. to make the haystack smaller. You'll find there are a lot of needles hidden in that smaller haystack...
