Sounds great! It's always those 'little extras' that don't cost much themselves so you ignore the cost, but when you've bought it all you realise you've spent an extra £500 or so! The fact that many were included is therefore great - especially for the price you paid!
Our headlining was the same. I believe it's a common problem for the factory fitted headlining to droop down. I remember someone saying it was a bit like a Bedouin tent! We replace ours ourselves last winter. It was a relly crappy job... and if you DIY I highly recommend a decent dust protection mask, as I understand the dust that's generated from the old polyethylene foam lining is quite carcinogenic if inhaled.
In case you need to know, we used:
Foam backed vinyl headlining from eBay - We purchased 10m (about £140) and used about 8.5m of the 54" wide stuff.
SAF111 Brush on contact adhesive from HawkHouse.co.uk - We purchased 2x 1 litre tins, and use every last drop, so I'd buy 3. This paints onto the inside of the cuddy.
Trade Tack spray contact adhesive from HawkHouse.co.uk - We purchased 3 cans, and used every last drop and even that was a bit more sparing that I'd prefer, so buy 4. This is sprayed on to the foam back of the headlining.
Plastic 'T' joining strip and the double sided adhesive tape (not normal DS tape... much more effective, so don't scrimp!) from HawkHouse.co.uk which has made a really neat and very easy centre joint down the middle of the cuddy.
All in, it cost about £220 with postages and stuff. Like I say, it's a faffy job, and a bit messy. Providing you have everything prepared and work in the correct order, and have everything prepared and ready to go, the adhesives are fairly forgiving meaning you can reposition your first 'stick' if it's not quite right (as long as you only tack a few points on the headlining). It seems like it's a two person job, but other than an extra pair of hands to get the contact adhesive on as quick as possible and a helping hand with the first stick of the headlining, there's not enough room for two, and the helper just gets in the way. I was the main fitter, and it wasn't too hard to do as a mainly one-person job anyway.
It's not an immaculate job, with one or two crinkles where the headlining stuck to itself and puttling it apart left a slight crease where the vinyl was slightly stretched), but you only really notice them if you go looking for them . Also, there's a lip around the inside of the cuddy door that needs you to curve the headlining around a 3D profile. It's such as small amount of bare GRP I just didn't bother. I planned to just paint/flowcoat it white, but haven't been bothered and you really don't notice it.