tire inversion at full pressure is normal and, just in my opinion, harmless.

I am not sure that rim you show is a tubular rim. Those side walls that seem to come up straight look clincher-like, not like the tire bed of any tubular rim I've seen in the past 37 years.

If your tires are old, but look good, hold air, exhibit tread retention, and do not have nicked sidewall threads, they are worth inflating on the rim, and if they hold air and still look ok, they are worth riding on. If you are gonna have a flat due to a failure, you'll have on. As with any new part or new repair, start gently, gradually increasing the demands you are placign on the new part.

I at least am not a good enough mechanic to fully trust my own repairs without a period of observaion and confidence building. If you do this, you'll find our safely and certainly if you have a tire problem.

Don't just go by our enthusiasts' advice, test it yourself.

Road Fan