They are also available in a wide range of brands and prices on e-bay:
The 91A2140 1 1/16" MC is part number
FD1050.
The 91T2140 1 1/4" MC is part number
FD4570.
And just to confuse the issue, your 1/35 scale model doesn't look like either of these, it looks more like the 1" bore M/C:
FE1476.