With my 'Rediscover Grammar' by David Crystal to hand, I've been struggling with trying to draw a tree diagram of the below sentence all day. I'm not asking anybody to do the diagram for, but I'm struggling to identify the independent/subordinating clauses and I'd greatly appreciate any help:

"And I saw a man with a newspaper and a bag of golf-clubs go up to one of the doors of the train and press a big button next to it and the doors were electronic and they slipped open and I liked that" (Mark Haddon, The Curious Incident of the Dog in the Night-Time, p.191)

* 'And I saw a man' = Independent, Main Clause
* 'with a newspaper' = Subordinate Clause
* 'a bag of golf clubs' = This could stand independently, but its connected with a co-coordinating conjunction to the last sub-ordinate clause - so aren't they both co-ordinated but as subordinated clauses, to the first main clause?
* 'go up to one of the doors' - Further confusion. If this sentence began with 'he' and was in the full past-tense like the majority of the novel is, then 'He went up to one of the doors' would be an independent. But because it just says 'go' I'm assuming it is a subordinated clause.
* 'of the train' - subordinate clause.
* 'press a big button next to it' = again, like with 'go', the use of
the simple present tense 'press', means its subordinate? It could be
independent if it were in the past tense, like: 'and he pressed a big
button next to it', but even then it is unclear what 'it' is in
anaphoric reference to - so still subordinate clause.
* 'the doors were electronic' - main/independent clause (?) - again, this throws me - how would I draw this whole sentence in a tree diagram? It would be easier if this very long sentence were split into two and it feels like this could be the start of a whole new sentence, if arranged by parataxis: 'the doors were electronic. they slipped open. I liked that'.
* 'they slipped open' = they, referring anaphorically to the doors, so therefore sub-ordinated? Or could it stand alone - despite it being clear what the pronoun 'they' is referring to?
	+ 'I liked that' - A subordinate clause, with 'that' acting as a relative pronoun referring to the previous phrase 'the doors were electronic' and 'they slipped open'.

I'm sorry for all this tediousness, I feel like I'm really overthinking it... I'd greatly appreciate help sorting through this muddle.