After a late, long chat with Manoel about which wheels we where going to use, we found some interesting links to where we could buy some.

Here they are (I also posted them for us in case we forget them) :

1st idea https://www.befr.ebay.be/itm/300919651560

2nd idea https://www.befr.ebay.be/itm/370376940748

3rd idea https://www.2ememain.be/auto-pieces-accessoires/pi%C3%A8ces/ligier/ligier-js6-pi%C3%A8ces-divers-aussi-300528328.html

4th idea https://www.amazon.fr/dp/B01N5HPB9P/ref=cm_sw_r_cp_api_ztTdzb2RNPE28

The 4th one is probably the one we'll end up using, as it's cheap and, well because it's cheap.

For the sprockets, we'll firs search in a scrapyard or something, but of we don't find anything, we'll probably buy some of those : http://www.befr.ebay.be/itm/35-Chain-Sprocket-9-10-11-12-13-14-15-16T-Pitch-9-525mm-For-3-8-35-06B-Chain-/152473406789?var=&hash=item23801f8d45:m:mYVo2KnvnOnbpvRAAwq5r4Q

The shaft diameter will most probably be 20mm

That's all folks !