I have added some hardware for the main-sheet to the boom and the transom. The boom is kept in place by a topping lift to the roof of the shed. The sheet is attached to the boom, runs down to a block on the bridle, then up to a block on the boom, and down to a ratchet block on the transom. This setup gives a 3:1 advantage. The SS loops on the underside of the boom only stop the sheet and the block from sliding.
This main-sheet setup keeps the cockpit clear and allows to easily hold the main sheet and the tiller in one hand, even through a tack. I have not made up my mind, whether the bridle is the way to go with a gaff rig. Most of the the old gaff cutters have horses instead of bridles, which has the opposite effect when sheeting in. Pulling the main close to the centreline, without a gaff vang in place, will introduce a lot of twist in the sail. A horse will reduce the twist, much like having the traveller of a boat on the leeward side. While having more tension on the leech and therfore a flatter sail, it won’t allow bringing the boom close in … This can all be checked ’empirically’ on the water, by attaching the ‘bridle-block’ temporarily to the leeward mooring cleat. We’ll see what works better.
In the photos, the bridle and the main-sheet are just bits of 6 mm cheap line and will be substituted with ‘proper’ double braided rope (6 mm / 10 mm). The bits of blue tape on top of the boom, are markers for the location of the clew(s) for fixing the cheek blocks for the outhaul and the reefing lines.