Hi Allen,
Congratulations on taking on quite a challenge, one could write a book on building a high gain IF strip and have plenty of material left over to write sequels. I get a sense of what you're doing but I take it you may have a lot of access to test equipment for troubleshooting. For starters, you might tell us how you are going about the project. If there are folks this inquiry you might benefit from additional and perhaps even better advice than mine. Have you built this on a printed circuit board? Do you have a schematic? Have you taken voltage measurements at all the nodes?
Most issues like you describe are most often due to construction errors. Although I haven't built the circuit (this was done long before I arrived at ADI) I've analyzed it in the past and it checks out as a valid circuit. If you're seeing saturated transistors you should look for wiring errors anywhere in the signal chain. The error could be due to a lot of things such as wiring errors, loss of or error in power supply voltages, open grounds, oscillation, exterminated input, etc.
I'm out of the office at the moment but will be back for a short while in December. Are you a member of ARRL? I used to build all kinds of equipment from their publications and found their QST magazine, annual handbook, etc. very informative, especially for a 15 year old kid (then, not now ).
I Hope this works,
James