Hey Sandra,

The song song can be identified in Florence E. Brunning's 1981 publication, "Folk song index," under the title Snowden Sleights (see below). From there, I found four additional references -- three performances and one journal entry:
- (undated): VARIOUS ARTISTS, Family Album (Long Man Records LM 4001) track A5, by Bryan Blanchard
- 1974: Don and Sarah Morgan, That Brave Commotion (EFDSS Records no cat. #) track A2
- 1978: English Dance and Song, Vol. 40 No. 1 (Spring 1978)
- 2006: Ian Bembridge, The Photograph And Other Short Stories (Bullenbush Music BB004), track 11

I haven't been able to track down recordings online of the former two, and no text/liner notes for the first, third, and fourth above (or if liner notes exist at all for either of the performances). Nor could I find an online edition of EDS, though perhaps someone on the forums has access?

Of Bryan Blanchard's song, Folktrax notes the following, which tracks with the remainder of what I found: "Born Selby and fowling is my trade" - comp by Blanchard & Morgan - descr duck-shooting in Yorkshire -- Bryan BLANCHARD (unacc): LONG MAN LM-4001

The liner notes from Don and Sarah's album explain the origin of the song (image from https://fantasy1564.rssing.com):

'Snowden Sleights' is an unusually fine occupational song written by our good friend Bryan Blanchard, who found the account of this fascinating character in his native Yorkshire (Sleights bio). By coincidence Don's home town of Poole, in Dorset, also has a wild-fowling tradition, its largely shallow harbour having a hundred-mile coastline of reeded mud-flats and saltings, heavily populated with wild-fowl. So when Bryan asked him to put a tune to the words Don was in complete sympathy with the feel of the song (to say nothing of being flattered by the request). Wildfowling was a dangerous, difficult and arduous way of earning a living, and the tune is, we hope, rather stark and harsh to match the character of the song.

I also managed to find the performance by Bembridge online (click). He calls the song "Wild Fowling" and credits the song as "Traditional." He has several additional verses, so I've reproduced it below. There are some minor dialectical differences between the stanzas which you wrote out above (italicized) and how he sings it, but I didn't bother correcting them.

SNOWDEN SLEIGHTS
(Bryan Blanchard)

Two ounce of powder and a pound of shot,
A hundredweight of punt gun lashed to a boat,
Wild geese and ducks in dozens have I shot,
Wild fowling is me trade lads,
Wild fowling is me trade

I come from Selby in the county of York,
With my gun on my shoulder I can hardly walk,
Nine foot barrel, one and a half inch bore,
Wild fowling is me trade lads,
Wild fowling is me trade

Me name is Snowden Sleights, I'm of humble rank
And me boat's dressed up like the riverbanks
So the fowl lie quiet til I've fired my shot
Wild fowling is me trade lads,
Wild fowling is me trade

I lay in me punt all cold and wet,
When the wind off the river would freeze you dead,
I pull the trigger and the boat jumps back,
Wild fowling is me trade lads,
Wild fowling is me trade

I've been wet and I've been frozen
I've shot wild fowl by the dozen
In a frost and flood I earn my living
Wild fowling is me trade lads,
Wild fowling is me trade

But when summer comes and the geese go north
I've another chance to prove me worth
Weaving baskets, they're the best ever made
But fowling is me trade lads,
Wild fowling is me trade

Two ounce of powder and a pound of shot,
A hundredweight of punt gun lashed to a boat,
Wild geese and ducks in dozens that are shot,
Wild fowling is me trade lads,
Wild fowling is me trade