Not at all..... all you need is a welder, a hammer, and a decent butane/propane torch
..... oh - and I'd advise making a saddle to run a tag down each side of the rear stay, not just one side: for comps, you MUST have two separate mounting points for the two separate shoulder-straps (3-point harnesses are no longer allowed)
If you have a scrap bit of tube lying around, use it, rather than working on the main cage
- Tack/clamp the mind-point of the saddle - try using a big vice as well as tacking.
- Heat the plate until its glowing cherry-red, and tap it round with a nice meaty meaty hammer.
- Keep working both sides, trying not to break the tack holding the steel in place.
Once you've made the saddle, you can shape it & get it in the right place on the rear-stay BEFORE welding it in place
(that's how I did mine, anyway
)