One of the IC types used on this board is a CA3081 which is practically impossible to find these days and there are seven of them on this board!

In reality this IC is made up of 7 pretty common transistors manufactured into a single IC package for ease of production assembly.

By replacing each of these IC's on this new board it can then be assembled using common transistors such as BC547's etc. This means the end user will need to install a total of 49 individual transistors but that is far better than trying to locate obsolete devices. It also makes fault finding in the future a lot easier.

You can see that IC26 has been replaced here with 7 transistors (ringed in white). Six more to go.........