Henslow Sparrow?

Hello Birders: On returning from an outing this morning (April 15) to concession 6 west of Walsingham to view the Greater Yellow-legs posted yesterday we were driving slowly on Woodword Side Road. north from Nova Scotia Line (County Road 42) west of Port Burwell. Woodword is not an all season Road and runs through a large expanse of corn stubble at that point, with weedy and grassy wet ditches and a few clumps of red dogwood and low shrubs. We flushed a short-tailed sparrow on the west side of the vehicle which flew along low off the ground a short distance and landed slightly in front of the vehicle about three feet off the ground in a dead raspberry cane. The initial impression of the sparrow was a totally coloured yellow head, as if the whole head had been dipped in yellow with a paler chin. A small area of the upper breast was lightly streaked but most of the breast was unmarked, with a slight band of narrow streaking at the sides below the wing. The lower mandible was pink with the upper bill slightly darker. Legs were pinkish. There was a white eye ring and wisker lines. The wings were somewhat rusty brown with no noticeable white. Alister Dennis-Grantham and myself observed the perched bird from the vehicle with field glasses, from about 20 feet for perhaps 20 to 30 seconds. His sister Clare also observed the bird with her naked eye. I remarked to Alister, "Look at that head, Have you ever seen one of those before?" Alister is 11 years old and already a very good birder but his response was in the negative.
In our initial excitement we all made the error of looking in our field guides at the same time and we lost the bird. We exited the vehicle and flushed a common snipe from beside a large pool of water in the corn field. We searched up and down the roadway and adjacent fields for about an hour, trying to refind the bird. We turned up a pair of song sparrows, two savannah sparrows and several horned larks but could not relocate our first sparrow. It was sunny, about 1:30 p.m. with light winds, about 8 to 10 degrees C. when we left the sight.
I realize how unusual this sparrow is and considered the Nelson's and Saltmarsh Sharp-tailed. However the breast was mostly white and streaking was minimal under the throat and to the side. I would be interested in hearing from anyone who may have an educated opinion or expertise on this sparrow. We will certainly be rechecking the location for future sightings.
Ron Allensen, Port Burwell.

Directions; Port Burwell is on Lake Erie at the southern terminus of highway 19 south of 401 from Ingersol exit. Proceed through town and turn right to cross the bridge. Proceed up the hill on Nova Scotia Line,(County Road. 42) round two turns going past Browns Road. continue on 42 for about a mile. Woodword Side Road goes north only (right) off of 42. It is wet gravel and sand. About a quarter mile up the road, 200 feet past the concrete culvert, is the spot the bird was sighted.