This is a great song. I wasn't able to find any tabs either.
I suggest working on transcribing the song by ear. There are great articles on this subject online and if you go to youtube and type "Chicago Make Me Smile Guitar Solo" there is a guitarist that has a great video of him playing solo that could give you some ideas of where to start.
I have been working on transcribing music by ear for the last year and I will admit that it takes a lot more work up front, but the long term benefits are well worth it. The more you do it, the better you get. Plus, you really start to notice details of the song that are otherwise easy to overlook :).
Tascam makes some really great guitar trainer devices that you can load MP3's of your favorite songs and slow them down without distorting the pitches. I don't own any of the current trainers - I used to have one of the older Tascam models about 6 years ago and it was did a pretty good job so I really want one again. I am sure the models out today are even better. If you want any suggestions on where to start with the transcription let me know.