Most likely, the springs are still in there, I think they are called a flat spring. When you take the brush out it unrolls but if you don't replace the brush it will it will roll back up inside the brush holder, It's just hard to see. They are attached in that holder is why I think they are probably still there. You should see it at the bottom of the brush holder, stick a little screwdriver or something in the middle of the spring, and roll it back out. I did the exact same thing, I could not figure out how I lost the springs...
As far as brushes, I ordered a pair off Amazon that were a little too big but same layout {copper wire coming out of the back at the top) then sanded them down to the same thickness and width as the ones that were in there. I used a belt sander, they sand down in a matter of seconds. the ones I used:
ECSiNG 4Pcs Motor Carbon Brushes Containing Copper Sheets Carbon Brush Size 9x13x25.5mm Replacement Carbon Brush $11