Sorting lines out

All straightforward. You have identified the key halyards - the green one is the jib halyard which would normally come down the port side. The blue line is a spinnaker halyard or spare jib. It is on a block ,like that so it is forward of everything else. That would also come down the port side. The block lower down will be for the spinny pole uphaul. Don't know what the double block is for in the right position for a burgee but way OTT for that!.

All the halyards could be 10mm but 12mm is OK.

Posting this photo with you first question would have got you this response (or similar) immediately.
 
Just a thought, I always specify a topping lift the same size as the main halyard, and use a shackle that will fit the mainsail. That way I have a spare main halyard - not that I have ever needed it, but have heard of others having the main halyard chafe through. Also, gives a safety line if having to go up the mast.
Excellent point. That's what I shall do.

The tufnel block on the side with para cord should only be used as a burgee halyard, or similar, as the small eye on the mast will not take any significant load. I do not see any reason for a double block in that position, a small single will be sufficient. (With any boat the previous owners always had some strange ideas).
Would it suffice for say, lifting a dinghy or outboard?

The block on the front with the blue line is intended for the spinnaker (or spare jib) halyard, however, I suggest changing the block for a swivel block as its movement is limited by the eyes and shackle. I have had a spi halyard jam between the cheek and pulley in a block (when lifting a dinghy) because the block was not free to fully swivel and keep the halyard in line.
(y)

Your spinnaker pole track could be for stowing the pole vertically. In which case there should be up and down hauls and a slider for the mast fitting on the track. To stow the mast end of the pole is hauled up the mast and the outboard end lives in a bracket on the mast. A fixed pole topping lift is fitted from a point above the track. To use clip the sheet in the outboard end of the pole and haul the mast end down the track. The outboard end swings up and out supported by the topping lift. If you don't have the fittings described and the track is too short to take the pole vertically you will have to fit the pole manually when needed. The line from below the radar scanner was probably used as the pole topping lift, but like the spi halyard needs to be free to lead out to either side so should really be on a swivel block.
There's what looks like winch handle pockets attached to the deck for the spinnaker pole to rest in. It's not very secure though and I hate it being on deck. I understand how you describe fitting the pole to the mast and the only obstacle to that is there is nowhere to fix the top end, it would simply hang off the pulley, so might rattle in wind and when sailing. I'll have another look tomorrow and see what I can do though.

You've been a massive help thanks.
 
Would it suffice for say, lifting a dinghy or outboard?

No, I would not risk it. The eye is attached to the mast by what looks like two self tapping screws. For comparison your wind instrument sensors are attached by 4 slightly larger screws! Out of interest can you ask the previous owner what it was used for?

I understand how you describe fitting the pole to the mast and the only obstacle to that is there is nowhere to fix the top end, it would simply hang off the pulley, so might rattle in wind and when sailing.

Yes, spi pole stowed on the front of the mast can get a bit noisy as it hangs off the pulley. My cutter rig has two for running with twin headsails. I solved the problem by making foam pads to stop the rattling. When properly set up they are very easy to use, even single handed, to pole out the headsail.
 
Top