It took me 450 hours to get the 25 solo sign-offs. Only about five of these were supervising other instructor's students, the remainder were mine.
The first 10 took over half a year [the horrid winter and spring did not help], the last 15 three weeks as all of the sudden all my students were at the right stage and flying frequently.
The reason nobody likes to employ restricted instructors is that in order to supervise you, normally another instructor needs to be present [and if done properly, also spend some time with your student notes, sit in on a couple of briefings]. The presence bit can be difficult to arrange at small schools. Even with three retained instructors at my school, I found myself without cover on occasion and had to cancel / rearrange lessons. Also, since you cannot send anyone on their first solo off your own bat, you need to be careful to have someone on standby when your students are about ready.
Instructing is great - I went into it after around 700hrs private flying and am enjoying every minute. I have no real interest in airline flying. Trial lessons can become a bit of a drag at times, especially the ones with little prospect of getting a student, but 80% of my students did their trial lesson with me, and some others as well.
Two months to get the instructor rating sounds about right, allowing for weather issues etc.