I have sheared the studs that fasten this to the exhaust manifold which bolts do I need to replace them with please?

Here is the muffler: https://www.lsengineers.co.uk/muffler-genuine-honda-no-18310-zm0-010.html Here is the gasket: https://www.lsengineers.co.uk/exhaust-gasket-for-honda-gc135-gc160-gc190.html The part number for the bolts (90004-Z1L-000) has been discontinued so we cannot get these anymore.