Verify Freewheel vs Cassette:
https://www.sheldonbrown.com/free-k7.html
DNP Epoch makes a 11T, 7-Speed Freewheel.
https://www.amazon.com/DNP-Epoch-Fre.../dp/B007A8RPUS
The one I had was slightly wider than the average 7 speed freewheel, although that might have been changed. But, in many cases you can just flip around a few spacers on the rear hub and redish the wheel to make it work.
Friction Shifting, of course, is easier to deal with than indexed shifting if you change the number of sprockets.
One issue that I had with the DNP Epoch is that it skipped a number of sprockets.
11-13-15-18-21-24-28.
In particular, the 12T and 14T would have been very nice. Anyway, I found the gaps in the freewheel were unacceptable, but that led me down a rabbit hole of changing from a freewheel to a cassette, and trying to get higher gearing and fewer gaps in the cassette. And, thus more speeds... 5s, 6s, 7s, 8s, 9s, & 11s (I seem to have skipped 10s for various reasons).