boom gooseneck ideas

[osteoderm]

Was your boom ever equipped for roller-reefing? Many such booms have been converted to slab-reefing these days. The sliding gooseneck offers advantages, but one of the biggest ones is that it could be used with a roller boom to prevent the boom-end from dropping when reefing; instead of the clew going dropping down, the tack is "wound back up" after dropping it to the bottom of the track whilst easing the halyard prior to reefing.
Sliding goosnecks also do away with cunninghams (although i've seen both rigged together). Personally, i think a hauled gooseneck looks smarter than a hard Cunningham with all the accompanying wrinkles. On boats of your size, it's pretty straight-forward to haul the halyard 'sans winch', then use a simple gooseneck downhaul tackle to get the required luff tension.
On th'other hand... sliding goosenecks are just one more set of moving part to be attended to. In combination with a vang, you can get some annoying jam-ups. Unless your topping lift is well-set, and/or your canvaswork is low, sliding goosenecks can allow the boom to wreak havoc on your dodger, bimini, or the boom itself.
Others will likely know better than i, but as far as i know, there are no sources for new parts for the burly Merriman sliding gooseneck/roller-boom fitted to my own boat. Perhaps other manufacturers are better-supported.
However, these good ol' bronze parts are tough kit, and generally shaped to be easily reproduced by a quality foundry. So long as the parts aren't cracked or otherwise too far gone, ovalised holes can be carefully overbrazed and redrilled, or bushed with new (pressed-in) metal.
Completely replacing a gooseneck arrangement tends to be the sort of work that avalanches out of control, sometime requiring other boom/mast mods, or sail mods to accomodate changed tack offsets, etc. My advice would be to look hard at repairing your existing sliding gooseneck, so long as there's nothing about its operation or performance that particularly bothers you. Don't feel compelled to modernize for the sake of modernity!