Yes- 2.5m is the minimum focus. The focus on my J-11 was good from 2.5m to infinity, and the transplanted 13.5cm F4 is also good across full range.
I will get a new thread up under adapted lenses, and probably this forum. It will be valuable to show pictures of your original in the same forum as my conversion. There are differences - easiest to spot is the lower-case "m" on yours.