I would like to replace the BB of a 1970 (or 1969, I'm not 100% sure) Allegro Anquetil in order to install a sealed square taper BB instead of the original cottered BB.
Since it's a 1970 Allegro (thus made in Switzerland), I think that it is reasonable to expect a swiss threaded BB. I'm looking at 2 options:

1/ Velo Orange threadless BB, to be safe (if it's not a swiss thread and/or if the thread is stripped)
please paste in your browser velo-orange.com/collections/bottom-brackets/products/grand-cru-threadless-bottom-brackets (sorry I'm not allowed to post URL's yet)

2/ IRD QB-55 Quad bottom Bracket with IRD conversion BB cups
please paste in your browser store.interlocracing.com/qbqubobr1.html
please paste in your browser store.interlocracing.com/italianbbcups.html

Should I choose option 1 or 2? Or is there another option that I'm not aware of?

Does anyone have any experience with Velo Orange and/or IRD products ?

Thank you!

3, Phil Wood uses the same BB cartridge,
only the mounting rings differ, and they make them in all threadings.

their mud shield rings, added , increase the contamination resistance..

If your BB shell is indeed Swiss that locks you into the high priced options listed. Swiss shell should be the right diameter
for the Velo Orange threadless BB which is limited to max of 35mm ID on the shell. All three companies have a good
rep (Velo Orange, IRD, Phil Wood ) but Phil will be even more expensive than the other two. I would go for whichever is
available and cheapest. A brief search did not show other threadless BB options but I believe there are some.
Amazon has this: https://www.amazon.com/Sunlite-Threadless-Repair-Bracket-122-5mm/dp/B001644PSC/ref=pd_cp_200_1?pf_rd_m=ATVPDKIKX0DER&pf_rd_p=fcaa6d12-8b2b-4ad7-b277-864b2da79f6e&pf_rd_r=EF3J8T28QFYK3AJ6B3BT&pd_rd_wg=95uRK&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&pd_rd_w=4OGKA&pf_rd_i=desktop-dp-sims&pd_rd_r=18daf808-a4a6-11e8-ab43-b9b76271e88c&pd_rd_i=B001644PSC&psc=1&refRID=EF3J8T28QFYK3AJ6B3BT

Cheap enough to experiment with.
Phil needs a special tool for their rings, maybe IRD also (?)

You also need an estimate spindle length, top of the head length guess would be 118 or 122mm for double CW setup,
purely a guess.

I'd start with the Sunlite option first. Niagara Cycle Works also stocks them. And there are undoubtedly other sources too. Pick the correct spindle length for your new crankset.

Hi Kovkov, thanks for your answer. The drive side cup is still fine but the spindle is not the original one and I strongly suspect that the one in place now doesn't have the correct dimensions since there is play in the BB. Since I don't know anything about spindles (their radii and/or models) I'd rather play it safe and get a new sealed BB.

Hi everyone, I'll make sure it's a swiss thread and then I'll order from IRD. Thanks for your input.

Its now a brand name, of Merry Sales Imports in California..

IRD was a few guys in Selma Oregon building Mountain bikes..

Have you purchased a crank yet? The spindle length of the bottom bracket you buy has to correspond to the spindle length required by the crank.

Despite the frame being Swiss be very certain of the bb threading before buying anything. It may be English, French or Italian also.

My Cilo is made in Switzerland and I thought for sure it must be Swiss threaded and dang it, it was French so I have an extra Swiss cup laying about. I went with a QB-95 on it and it is smooth as butter but was difficult to remove the old BSA cups. Phil Wood also is a nice choice because you can literally get any sort of threaded cups and was the only choice for my Phil Wood frame but alas their newer stuff loses the red engraved logo which bothers me a bit even though nobody will see it.