Sabre steam steam dome?

[ZingyOrange]

I think you're describing the "Silver Lady" steam dome. This is available from Roundhouse. I'm sure there is a price on their website somewhere.

 

[Rhos Helyg Loco Works]

Sabre used a Roundhouse "Silver Lady" dome, but the boiler filler valve was underneath and not part of the dome itself.

 

[New Haven Neil 2]

I fitted one of these to my Fowler - you need the Silver Lady filler valve/filler plug too, as the inside of the dome is a bigger diameter than the original. Contact Roundhouse, they ARE as helpful as their reputation! Harri Harrison will sort you out. wasn;t a great deal of money.