I travelled last night- the reports of 30 odd passengers to me seem about right. Of those a handful (stereotyping wildly here, I'm aware!) seemed not to be enthusiasts.
Plus points: very comfy seats, beautifully restored and very clean mk3s, friendly staff and tasty drinks at a reasonable price from the buffet car. Once aboard, we had regular updates on progress. For me as an enthusiast, it was a fantastic trip. However...
Negative points: the e-ticket went straight to my junk folder, and I had to go and dig it out. The email came with no clear confirmation of departure time or instructions on what to do when arriving at Euston, which I think a "normal" passenger would require. Fortunately on arrival at Euston, the departure boards prominently displayed "Charter Train"- it would've been helpful for a regular passenger if the ticket had made that clear.
Upon then making it over to platform 16, the train was sitting in the platform, lights on in most but not all of the carriages- this was about 40 minutes prior to departure. Again, as an enthusiast it was nice to wander up to take a look at the loco, then take some time to wander back onto the concourse for a Burger King, but I think a "normal" would have appreciated a welcome at the top of the ramp from the LSL staff.
I think this has the potential to be fantastic, but there are quite a few creases that need to be ironed out if this is going to be more than simply an enthusiasts' jolly that's presumably costing Hoskings thousands. Facebook advertising would probably help, and a more sustained media campaign?
A final and heartening comment: the group of enthusiasts on the platform ends at Euston I noticed had a good deal more ethnic diversity than I'm used to- which can only bode well for the future of our hobby.