Charles,
I live in PA and we have very little regulation on construction here compared to other states so I don't know if this will work for you or not, but this is what I would do:
If you're not already, Incorporate.
Register your old business name as a fictitious name under your corp.
Register a new fictitious name for your specialty bath company under your corp.(fictitious name registrations are done through your Secretary of State's office i believe)
Now you can do business under both names and promote them together or seperately as you prefer. You could even market the new one as "upscale bath remodels" and do any "non upscale" work under your old company name etc.
www.rubycon.us
Ruby Construction LLC
Lancaster Kitchen Remodeling
Lancaster Bathroom Remodeling
there's my 1/2 cent