Some times a spare part won't work because the pin length will be off if it isn't the right depth. I have made pins out of finish nails before but it does have to have something to hit. Does the Brant tensioner have a bar for thread to pass around just before it goes through the take up lever? The Riccaar has a plate type bar in the parts you have - it is the last pass for thread before the take up lever. The new tensioner does not seem to have a bar or a plate type bar for the thread to pass before the take up lever. The easiest solution would be a whole new nose plate with a working tension.