I ma amazed that it is almost 5 months since I posted and since then I have been playing through the amp every day. I have a few observations on tge amp and some mods that I will be doing. After some discussion with @Passinwind who designed the pre-amp, I will be modifying the treble control. Although I rarely boost treble and can cut it on the Tone pot of the bass, it seems odd to have a control that seems to do nothing.
Secondly, I always needed to add an HPF as the speaker can only go so low and it is a waste of energy and headroom to let those frequencies through. The plan is for a fixed frequency 24dB/octave with a -3dB frequency of 50Hz. This may seem high but it has little effect on the real frequency response of the cab and means that at 100W, the cone excursion is well within the speakers capabilities down to a few Hz.
Finally the power amp is capable of 100W into 8 ohms and 170 Watts into 4 ohms. It's just asking for an extension cabinet. So a Fane 8-225 speaker will be fitted into a matching box to utilise the whole power of the amp. So 2x8 stack fed with170 watts, ideal for my open mic gigs IF they start up again.
Finally (for this post) a big thank for their help in this project you to @stevie, @Phil Starr and to @Passinwind