Where can I find the part numbers for numbers 83 and 84

Please see the links below: 83 - https://www.lsengineers.co.uk/cooling-plate-genuine-stihl-part-oem-no-1147-141-3200.html 84 - https://www.lsengineers.co.uk/catalogsearch/result/?q=1147+149+0600