[DeTomaso] Brake Master Cylinder Issue

[Bill Cartus]

My brake master cylinder was leaking so I took it off. I can easily see that the problem is the larger rubber 'o-ring' has a small crimp in it (not sure how it was even working unless the rear portion was doing most of the work), but it appears no one sells a repair kit (per Wilkinson rep I talked with). I can't see spending $289 for a whole new master cylinder when a $1 part will take car of it.  Does anyone know where I can get these parts? Has anyone used an after market unit from Summit Racing (as an example) replacing the tandem unit attached to the booster?  I have a 1972 car and assume it has an Italian factory replacement unit from around 2016. Attaching a small pic below.  All advice appreciated. 
Thanks,
Bill Cartus #3633.
-------------- next part --------------
   My brake master cylinder was leaking so I took it off. I can easily see
   that the problem is the larger rubber 'o-ring' has a small crimp in it
   (not sure how it was even working unless the rear portion was doing
   most of the work), but it appears no one sells a repair kit (per
   Wilkinson rep I talked with). I can't see spending $289 for a whole new
   master cylinder when a $1 part will take car of it.  Does anyone know
   where I can get these parts? Has anyone used an after market unit from
   Summit Racing (as an example) replacing the tandem unit attached to the
   booster?  I have a 1972 car and assume it has an Italian factory
   replacement unit from around 2016. Attaching a small pic below.  All
   advice appreciated.
   Thanks,
   Bill Cartus #3633.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Mstr Cyl 3633.jpg
Type: image/jpeg
Size: 42326 bytes
Desc: not available
URL: <http://server.detomasolist.com/pipermail/detomaso/attachments/20200304/2d07f17b/attachment.jpg>