Branson 8050, IH 574, Oliver 1550 Diesel Utility (traded in on Branson) NH 8160. Kioti CK2620SECH
They likely can be filled. However I doubt that they have the "normal" liquid fill valve stem.
Such as this one for a tubeless tire;
Also with a volume of only about 2 1/2 gallons per tire the weight increase is not much for all the trouble.
Bolted on iron on the front of the tractor would be easier and likely faster.
Ford: '88 3910 Series II, '80 3600, '65 3000; '07 6530C Branson with FEL, 2020 LS MT225S. Case-IH 395 and 895 with cab. All Diesels
Problem with a drum mower is that in the mow position and elevated (off the ground) the left front wheel is usually too light to keep it on the ground. I would suggest front weights in addition to any tire changes you are contemplating.