I think I should make an appointment then at the opticians
However, my experience of mixing mild steel and stainless exhaust systems (albeit on classic cars), is that due to the differing expansion rates of mild steel and stainless, it isn't always easy to maintain a gas right joint, especially on male/ female sliding joints. A heat resistant red silicon allows for slight movement whilst maintaining a gas tight seal, and it also aids subsequent separation of the joint, whereas an exhaust paste sets rock hard, with no allowance for expansion movement, and is horrible stuff to remove if you need to separate the joint at a later date. Bolted flanges such as the cat to centre section as on the Omega stand a better chance between differet metals, but I would either keep to all stainless or all mild steel.
With the red silicon, there is also no need to overtighten the clamps - nip them up firmly to hold the two sections together, but overtightening only deforms the pipe, and makes later separation difficult. I would also try and source or reuse the original VX style D clamps, rather than use U clamps, as U clamps are more likely to put an indentation in the pipe it is clamping which makes life difficult when separating later.