The spiked board is for shredding flax to separate the fibers. A handful of flax was held in the hand and thrown like a whip onto the spikes then pulled to separate the fibers. I think that using it for hemp would be another use for the tool.

ive seen something like that board with spikes in it before when working in wool industry .could be a tool once used in combing stage of shorn fleece wool production. probably done with machinery now . i think its the process after scouring wool to clean and remove tallow .

Sorry, they did not hit the back of the plane with a hammer to "drive it through" but to loosen the blade for adjustment

I used to use the sycle in ky to cut weeds they stilll aale them in the area im from to use today

at 16:50 In the country you're in it's called a hackle, (hemp)

very cool. i have an adze exactly like the one they showed and though i couldnt make out the markings on theirs it looks just like the markings on mine. very cool ship building tool from the mid 1800s

wanted to comment on this just cause the count was low.... these guy are awesome

at 10:44 It's not broken. It's called a caulker; in Dutch: breeuwhamer. It never had a handle, it was used together with a hammer. museumrotterdam.nl/collectie/item/48218

at 4:54 are two hay saws put together. www.bladeforums.com/threads/obsolete-knives.1355582/

Many plane bodies were made of a fruit wood. Pear, apple or other type fruit wood. Your Jack plane appears to be pear but a closer examination i s needed to confirm.

is the board with spikes at 17:30 for shredding hemp to make rope?

looks like a 5/8 bit

is the tool at 5:03 a ice saw ? or a peet cutter?