16 or 8 ohm speaker ?

[Mark Hennessy]

The change in impedance might make a slight difference, but probably not as much as you might think in practice.

However, it is a completely different loudspeaker, and that will definitely alter things. There are a lot of parameters in a seemingly simple loudspeaker.

If possible, tracking down the exact unit would be best, but a similar speaker from the same era would probably be a big improvement. What sort of size is it?

Hope you're feeling better now