I just read your blog with some interest because I am your same age and located in the SE Wisconsin area. I also re-started my own small engineering & surveying company a couple of years ago after a 6-year hiatus, thus I had to address many of the same issues you are discussing in your blog.
Easiest option to improve "passive" lead generation is link your webpage to your directory listing on the Wisconsin Society of Land Surveyors (WSLS) website. This will provide you a lot more web search exposure. It goes without saying that you should already be a member of your national, state and local chapters. I do not recommend paying a consultant for website SEO improvement.
You also need to really step up your "active" lead generation efforts because you have been out of the marketplace for so long. A good place to start is calling up your past clients and reconnecting with them. Then you can find out what opportunities they have available for you and/or request their referral to new prospects. Secondly, explore opportunities to partner with other firms in your area, whether they be engineers, contractors, architects, or even other surveyors. Being a 1-man shop provides you the flexibility to do that quite effectively. Finally, look at joining your area realtor association, chamber of commerce, rotary, or other such organization to get your name and company recognized as a resource available to other business owners and leaders in the area.
All of the marketing & sales efforts mentioned above have worked for me. You just need to be willing to schedule the time and effort necessary because you can't expect anything to happen overnight. However, consistent effort on your part will produce the results you are looking for.
Wishing you "Good Luck & Good Fortune!"