Without knowing exactly what you have in your log now, it's hard to say what it will take, but at the end of the day, to add the ASEL to your current certificate, you'll need the following time in airplanes:
10 hours of training in a complex airplane
5 hours of instrument training
2 hour day VFR XC flight with an instructor
2 hour night VFR XC flight with an instructor
3 hours of test preparation with an instructor
10 hours of solo
10 hours of solo XC
5 hours night solo, including 10 takeoffs and 10 landings
Note that many of these can be combined, like doing all the training in a complex airplane (you can fill all the training squares in as little as 12 hours total), or doing the test prep in a complex plane, or doing some night solo XC with a lot of landings (night solo and XC time). No written required. In theory, you could do this in as little as 22 hours dual and solo, but it ain't easy making that work.
That said, with 25 hours of airplane training logged, it's almost certain that you'll be in a "train to proficiency" situation as far as the dual time is concerned. Also, you're not likely to have all your solo time be solo XC. In addition, since a lot of flight schools don't like letting students fly night solo XC's (even with your background), you may have to do around 15 hours of solo work (10 day XC, 5 night pattern) or more -- depends what you can work out with them.
Once you add that ASEL to your CP ticket, you can add the IA rating with an additional 10 hours of instrument flight training in the plane (the 5 hours from above counts towards the required total of 15 hours of training). Note that it may take 12-15 hours of flying to get 10 hours of instrument time, because the hood's not on all the time. You won't have to take the instrument written since you already hold a IH rating, but there will be another practical test.
