Morris Minor Owners Club

Hi I’m trying to find an original or pattern rear blanking plug for a master cylinder that currently has the esm remote reservoir on (you replace the original part with a version that has a hose tail on) its leaking everywhere and I want to either remove or tap the original cap to take a banjo? Cant find one for sale just wondered what my options where, trying to avoid machine a brand new part

The original and pattern rear blanking plug threads are different.
I would suggest that you fit a new annealed copper washer and use Loctite thread sealer on the washer , threads and tail.