Is there a seal kit from another source that I could use for my 87 T5…? Gutsibits say this isn’t available any longer… 
https://www.gutsibits.co.uk/prod_img/lrg/IMG_2488.jpg
There MUST be something out there that uses the same rubber seals, just need a bit of lateral thinking, and that’s not my strong point… 
Over to the team…
OK so it’s this -
How about this one? Not sure if it would fit or not?
https://www.ebay.co.uk/itm/BREMBO-PS12-MASTER-CYLINDER-REBUILD-KIT-/181227749444
It looks supply of the spare kit is running out. Not sure if the one above would fit or not. The alternative is to fit any old 12m master cylinder, assuming the cylinder isn’t part of the switchgear. Something like this maybe
https://www.ebay.co.uk/itm/MOTO-GUZZI-NEVADA-750-FRONT-BRAKE-MASTER-CYLINDER-LEVER-ASSY/292432514697?hash=item4416560e89:g:N~4AAOSwTEJaIrjY
It would be worthwhile checking if you can get seal kits for this as they are not made for some newer master cylinders.
It is indeed for the front brake master cylinder, which Gutisbits say is a trapezoid handlebar mounted reservoir jobbie, which is all part of the switch gear, so a massive job to swap out, if I can’t get the stupid rubber seal, when the ones in there, go on the wonk…
So I was just wondering, if anyone knows where I could get the seals, don’t need the piston or the spring, I DID call Gutsibits, and the lad on the phone says I’ll have to swap out all the lever, switch gear and everything. Don’t really want to get involved
in that marlarky if I can help it… 
If all else fails, and if DOES come to that, I’ve got a set of Yamaha gubbings I can use, as and WHEN I need too of course… 
Is it like this one?
https://www.ebay.co.uk/itm/Moto-Guzzi-Magura-Front-Master-Cylinder/173138911983?hash=item284fe222ef:g:3IIAAOSwVVRadfNq
That one is made by Magura, not Brembo and seal kits are available, but they are around £60.
I had what I think (?) is the same problem with my V65 Lario that has a trapezoidal MC integrated with the RHS switchgear. I too had the conversation with Gutsibits re changing the controls and unobtainable parts.
The solution I found was to order a Brembo M/C piston kit for a piston of identical diameter. It is the shape that is unique but the diameter is common to other rebuild kits. Using fine picks, lubrication and patience I teased the seals off the new piston and put them on my existing one. Hey presto, it now seals!
I’ll put a photo up of the m/c for comparison
Magura MC.JPG
Cheers
Simmoto, that there is the self same one as my T5, and that reply is what I was after, thanks my man… 
A bit of lateral thinking, something sadly I can’t do…
No worries glad to help - it took me ages to get to that point, burning fivers along the way… -I hope it works for you.
I also found the m/c lid wont seal without a tiny smear of silicone
