["supercharging" your heater]

Nice work! Bilge blower seems to fit snugly into the duct.

[safari snorkel.]

My only experience is putting a Safari snorkel onto my LHD 130 2001ym TD5.

There it was only those 3 10mm nuts plus the bracket on the window frame holding it. The seal against the wing was done by a neoprene (or similar material) gasket.

So my guess is that the sealant on yours is arguing a little bit. For access, you can take off the wheel arc and have look in there. It comes off by pressing out the center of the plastic rivets (app. 15) and then just pull.

[TD5 Rev Counter Wiring]

I have just done this to mine, and this thread was of good help. Thanks!