Expired efke KB100, Ilfotec HC

I just started shooting 35mm BW and I need some help exposing and developing efke kb100 that expired in 1996.
Since film expired quite some time ago question is should I expose it as ISO 100 or should I rate it differently?
What usually happens to expired film, loss of contrast, fogging?
I only have Ilfotec HC and there is no chart for developing kb100 in it, can I use info that is provided for HC110?
My tap water is at constant 23 degrees Celsius, should I use it as it is and adjust developing time or should I cool it down to 20 degrees Celsius? If I need to cool it down what is the best method? (Ice, cold water from the fridge)

Your help is greatly appreciated!

Aleksandar

It depends on how the film has been stored mostly. What you usually see is an increase in film base fog, and a loss of speed. The contrast is usually not a problem. The warmer the conditions the film has been stored in, the worse these problems usually get.
If you have many rolls, may I suggest that you photograph one roll at an exposure index of 50, and bracket each exposure +/- 1 stop. Then develop it for the normal recommended time. 23 degrees C should be fine, but you will have to adjust the development time. I think Ilford has information on how much you need to compensate.

There is no real way of knowing how it's going to turn out since it is so long expired. Please let us know how it went.
- Thomas

Thanks Thomas!
Unfortunately I do not have idea how this film was stored but I will try to what you have advised me.
I only bought this film because I'm learning how to develop and this is some sort of cheap practice until I get better.
As soon I finish roll I will post results.
I also got Ilford HP4 (30m roll) that expired 2 years ago but I'm keeping that for later hoping that it is in much better condition.