I bought one of the original model Marauders 2nd hand and had it 1988-90 (yacht 2 of 12 for me so far....hoping to stay at 12...).
Top boat but the original model was designed with a trim tab on the keel to copy the 12m Intrepid who first used this - a bridge too far for a 24 footer but well done to Kevin Shepherd for trying it. 2 models followed as far as I know - the similar boat but with the trim tab filled in, then the Marauder 725. All were out of the same mould, the 725 had the alum toerail. A long cockpit which is perfectly proportioned for the boat - the cabin length and cockpit lengths are perfect.
sailboatdata.com/sailboat/marauder-24This link indicates first build 1975 but I think it was a few years before that they first came out - they did well in the JOG races over east here till the light brigade boats came out, and numerous have cruised up and down the east coast in suitable weather.
Great facebook site there - good that all the family can be involved - and that you have rescued it and refurbished it so well.
For your new main assume you will go fully battened - suggest 4 battens. Make sure it is not cut too full.
For your new jib what size is it? A no3 size blade or no2 or no1? Do you have a photo which can be posted? Main comment on jib sheeting is that potentially they can be sheeted closer inboard rather than out near the gunwale - so jib tracks up on the corner of the cabin and going to windward the boat should point higher - but have to be careful of choking the jib to mainsail slot as this will not be fast.
I preferred the centre cockpit traveller but certainly agree it gets in the way - would leave yours where it is.
For the tiller google "laminated yacht tiller" - many posts will come up eg
So build one yourself or expect this company would do it very easily.
www.oconnorwoodenboats.com/