Vocals are written under the tab!
The Tampa Kid was among the recording names of Charlie McCoy, brother of Joe McCoy who tape-recorded a lot with Memphis Minnie. Charlie was primarily understood for his excellent mandolin playing.
I came to understand the tune through Mike Dowling’s recordings. He tape-recorded two (slightly different) variations.
Here’s the Tampa Kid version

and Mike Dowling’s versions
cd variation:
live variation:
I remain in open D tuning but with the capo on the second fret which results to open E tuning.
I’m playing my “Louisiana” model Delta Resonator made by John Alderson of the UK

Time stamps for lesson
00:00 complete efficiency
03:49 spoken introduction with pointers on how to use the slide, nail care, muting and so on
09:54 introduction of song.
10:47 First verse slowly.
11:26 Very first verse discussed.
16:55 Second verse played gradually.
17:30 2nd verse explanation.
20:04 3rd verse description.
22:00 First solo played gradually.
22:45 First solo explanation.
26:10 4th verse description.
27:54 Second solo.
32:55 3rd solo.
37:16 5th verse and ending.