Yes, the loco is different, and so are the coaches! Chatting to the driver revealed that the line had changed operators over the winter (the track is owned by the council), and that the current owner had hired in the loco's and stock. Clearly some work had been done to the track and infrastructure too.
The line now has two "toastrack" style coaches with roofs and air brakes, and a rather attractive Bo-Bo bogie diesel, it has a resemblance to the BR class 17 "Clayton" I think! OK so a steam loco would be nicer, but if it is a diesel it might as well look like one, rather than pretending to be a steam loco when it plainly isn't. I couldn't find any builder's plates but the stock had the style of Alan Keef to me, which would be logical and the point levers were certainly from that firm.
At the Mewsbrook Park end of the line there had been some changes. The tunnel had gone (unsafe clearances apparently) as had the footbridge (which went nowhere anyway). The track had been relaid and re-aligned, and the layout of the shed changed, including removal of the turntable from in front. There were still turntable releases at the end of each station loop, and the new loco was a very tight fit for length! Indeed work was ongoing and the driver chatted to a man in an orange coat who was "fettling" the trackwork. I nearly suggested copperclad sleepers and soldered construction would be easier!
There is also now a website at http://www.littlehamptonrailway.co.uk including operating dates. Although a little on the pricey side for a short run, it is a very pleasant line and I wish the new operators well, I'm sure we'll be back again to see how they are getting on!