Good Morning Again,
Yes, you should be able to get to St. Peter's Dome by way of the Old Stage Road. The Pike National Forest Office says there is a trailhead to the Dome. You might want to check with them. The Old Stage Road goes from just outside of Victor down into the Broadmoor area.
We too spent a lot of happy hours prospecting the areas between Victor, Cripple Creek and Colorado Springs. Never found any gold off of the Gold Camp or Old Stage Roads but still lots of nice areas to hike in.
Hope this helps,
Goldenlady