So, after trying initially with a cutlery knife I'm ashamed to say, I followed the top tip of buying a heat gun. What an amazing tool! That tar rubbish didn't stand a chance. Still needs a clean up with some spirt cleaner perhaps, but all that shielding stuff as 5-10 kg you really feel it's weight when it's together in a bag!
More:
A lot of that wiring loom is for speakers so it will be gone soon. Also, I'm pleased to report my first sexy purchase is fitted!
Long way to go but it's nice to see a start! The OBC and loom has gone for £50 to a grateful new owner. Turns out part of the loom involves a temp sensor and alarm fitting the go right through the engine bay to near the front fog light... nightmare. Oh and the indicator stalk forms part of it too! Luckily, that wasn't so tricky to remove, and the buyer is sending his old inidicator stalk - the OBC version has a push button on the end. When this is in and sorted, I can get the wiring sorted for the new horn, as you can see is missing right now.
I've also given the girl a service so new oil filter and oil, spark plugs and air filter (eurocarparts were happy to exchange the filter I bought online which was supposed to be for my Car, but clearly wasn't!). The engine revs a bit more freely and feels sweeter. Not surprised - the last recorded service was 50,000 miles ago!