OK, an update and help required

The DIS is a right bugger to get to, no way of getting it out without removing the plenum and even then I can see it won't be easy. Who designed this crap?!
Anyway. I could remove sparks on the drivers side and sparks 3 and 5 (2 nearest to bulkhead) spark OK when trying to start (took plugs out). Spark 1 would not spark. swapped plugs and no joy so the plugs on that side are OK. So it looks like lead 1 isn't getting a spark.
How can I investigate further? I think I could manage to get a lead from the DIS at plug 1 but would need a new lead from somewhere - will any lead do for this test?
No chance of getting to the plugs on the nearside, again which idiot designed this thing... It's like they've made something that should be simple as tricky as possible. Even if I removed the plenum etc, could I then still do the spark test?
Also, the padding underneath the scuttle was soaked through (trying to dry it) and almost fell off. Do I really need to replace it? What does it actually do?
On the plus side, I managed to unblock the drain hole while I was at it
