Hello Don,
White Metal for use as Chainplates has got to be the very worst choice of metals ever !!.
Having served an Apprenticeship in Engineering, a "feeling" is developed over the years as to what will work and what will not.
Chainplates are subjected to quite considerable shocks and strains, least of all being bashed into the quayside when docking.
I would scrap the ones supplied with the kit and make some new, stronger ones.
Buy some Brass Strip, 1.5 mm thick, 6 mm wide, or as near as possible to the original ones.
Copy the original Plates, then file a Radius on the outside edges of the new Plates to prevent then being pulled off the hull when rubbing against the Dockside.
Fit the new Plates to the Hull, with another Plate inside, so that the screws are clamping onto the Hull, no need for glue !!.
Rig the boat up fully, place into the water, hold the top of the Mast and shake from side to side "with vigour", did it break?, if the answer is NO, go sailing !!!!.
Have fun !!.
John.
