But can I make a living at it?

[Lamplighter]

<snip>
Both are intensely satisfying, present their own challenges,
are interesting and I get a lot of support and kindness from the people I'm working with.
Neither is all that terribly time consuming right now,
and I can more or less work at my own pace - when it fits into my life.

In other words - the perfect jobs - for me - at this stage of my life. Only problem is: They don't pay a dime.

I keep thinking there's got to be a way to parlay this into a little income.

I believe you sentence above has set forth above the very basic issues you need in order to have a good start.

You say: "Only problem is: They don't pay a dime."
I say: You haven't given them a reason to pay you a dime.

To start, you need to create a professional, for-profit, image
so your "clients" have the immediate belief they need to pay you at your rates
.... freebees are for amateurs and hobbyists.

Here's the way I got started...
I first went an attorney to find out what was needed to establish a "sole proprietorship"
I next went to a CPA to find out what was needed with respect to taxes and my expenses
Then I went to the State Dept of Commerce and established my company's "Doing Business As":
My DBA was "Lamplighter Consultants"
Then a bank account for writing and depositing checks.

I then went to the local copy shop and ordered 100 business cards.
I also started collecting forms and draft of documents I would need,
(early drafts of contracts for scope of work, receipts, procedure manuals, advertising brochures, etc. )
... whatever I could think of to assure that I looked professional.
My "consultantships" changed a lot over the 7 years as I learned
what clients wanted/needed, and what they would pay for.

Then, I started contacting all those people with whom I had been "volunteering",
and told them that things had been going so well,
and that I enjoyed working with them so much,
I had decided to do the same kind of work professionally.
I asked them each of them if they had any suggestions or advice.
I did not ask them for work at that time.

Nothing happened for a while, but when several of the (annual) projects came up again,
those people knew I available and working professionally,
and they expected me to set my fees and conditions.
Sometimes one client led to another, and what had been
a volunteer activity became a nice extra source of income.

Since I was advertising myself as a "consultant", I was free to take
on any type of activity I wanted, to produce or farm out
whatever product(s) or services might be needed, etc.

IMO one important thing, however, is to set fees appropriately.
Your fees should tell your client they are now getting professional service.
At first it might be tempting to go low... but I suggest going as high
as you can reasonably expect for whatever service you provide.
That is, don't look for that $100,000 glass of lemonade,
but also make sure your fees are high enough that your time
with each client remains worthwhile to you and them,
and maybe even a tiny little bit higher than they want to pay... at first.

People tend to think they get what they pay for.
Somewhat higher fees tend to make them believe
they are getting better than a local volunteer or a "low baller".