buff-scrag

Hello gents, I'm just getting into the wonderful world of field recording with my new MZ-RH1 and AT822. I'm particularly interested in recording railway sounds here in the UK. I've already made my first attempt this weekend and am fairly pleased with the results - the AT822 really is an awesome piece of equipment! I just wanted to pose a couple of questions to make sure I'm getting off on the right track (no pun intended!). My main query is regarding the Recording Sensitivity setting on the MZ-RH1. Should I be using High or Low sensitivity for this type of field recording? And if so, what kind of recording level should I be aiming for? I've been using the high setting, but is this too much with an ultra-sensitive mic like the AT822? Secondly, I did notice some wind noise at the weekend (it was reasonably breezy). On one recording I flicked the low frequency roll-off on the AT822 which cut out most of the wind rumble. Would switiching to Low sensitivity on the MZ-RH1 also help with the wind noise, or am I barking up the wrong tree? Finally (so many questions!) I'm planning to do some onboard recording, basically holding the mic out the window of a moving train - I predict wind noise problems here! Any ideas on settings? I should say that I've got a Windtech 'Mic Muff' fitted over the AT822's foam pop guard. Anyway, thanks in advance for any advice you guys can offer - I've already learned so much from this excellent forum! Cheers, Nick