Help with ID of found bird's species, + need a bit of advice on care

[Sionnach Dhu]

I posted this over in the "I found a bird" area, but since it doesn't look like people read or respond much there, I thought I'd post here as well:

Last night I took my dogs out for a hike at a local park - 370+ acres of woods, fields, and so forth. When we got back to the car, I noticed that there was a pure white bird flopping around on the entrance road, clearly in distress.

Popped the dogs in the car and walked over, and found that the bird was quite clearly a tame pigeon or dove - no fear of me at all, readily let me pick it up and examine it, settled into my hands as I carried it back to the van, and eagerly hopped into the dog crate (cage) that I keep set up in the back.
It has an injured left foot - looks like it got pinched in something; broken skin and bruising on top, and swollen - which it doesn't want to walk on. I don't think anything's broken, it's just painful.

Took it home, dug out an old parrot cage from storage, gave it some bird seed and water; it ate & drank a lot, then settled right down.

I initially thought it was a white ringneck - not much of a cere, and it's not a very big bird - but after Googling a few more images, now think it may be a smallish Stielbacht or other white homing pigeon. I'd like some more "expert" opinions.
link to a gallery of six images: http://www.flickr.com/photos/cimawr/...7626868230475/

And one photo:

I also have two questions about care:

1) I've been washing the sore foot with warm water, which the bird seems to like. What other care would people suggest? Is there a topical antibiotic which is safe to use for birds?

2) I know the bird needs to have grit, but my local petsuperstore doesn't carry any supplies for pigeons. I'm probably going to have to drive 35 miles to a feed store, which I'm not going to be able to do for several days. The pet store did have oyster shell grit.. would that be safe to give in the meantime?

Editing to add: No bands on the feet, so no way to find an owner, unfortunately.