Here is the situation, I made a small circular trinket tray from a 4" diameter disk. I used a very small sinking hammer 1/2" in from the edge to bring up the sides of the disk so I now the sides are straight and just off the vertical.
At my teachers shop, she had a hammer that looked like a bordering hammer but there was more of a curve to the face. This curve is along the length of the hammer face so when looking down on to the hammer head the radius is along the hammer body and the center point is where the handle is.
BTW, what would you call this type of hammer??
I did not measure the hammer spec's and I did not see a name on it either but finding anything similar would be nice.
And I know I might have to modify a hammer to get what I want, but I am not set up for this YET.
It can be difficult to discuss hammers without photos to be sure of what you are talking about. I personally have forgotten what most of my hammers are called since I have purchased them all so long ago now. One thing I did was to purchase a lot of a German made raising hammer from Tevel at Allcraft (Google it in New York area) and then modify one to my needs when ever the occasion arises. I know you said this is difficult right now, but you should try to find a way because other than peening hammers, almost every hammer you buy will need to be refaced to your needs and polished. Maybe if your local high school has a shop you can trade mentoring time for use of their equipment.