Hi Crunchy,
I dont post a lot on here mainly browse it but thought id chime in . The guys on here are experts but you may want to try http://www.rctankregiment.com/rctankforum/index.phpfor info too as those guys are more local to you.If you need any parts contact memeber forgebear on rctr, he is a very helpfull vendor and gives great discounts to memebers.
The Mato metal stuff is just a metal remake of original HL design, I would reccomend this over it any day (plus cheaper!) <a href="http://www.welshdragonmodels.co.uk/asiatam-lower-hull-for-heng-long-tiger-1-with-metal-chassistorsion-bars-116-scale-512-p.asp">http://www.welshdragonmodels.co.uk/a...cale-512-p.asp
</a>Neither hulls are waterproof but it would probably be easier to do to Mato hull, I know there are people who have.
Always check ebay for bargains or ask around forums 'cos places like Tankzone relish the shortage of competition and maintain high prices!
Good luck mate, Dave