I understand it is a FRAM PH-3593-A
FRAM Part Number PH3593A
The Kubota oil filter 15241-32099 crosses to a NAPA #1064 or a Wix # 51064. NAPA filters are made by Wix. Hence the similar numbers.
Fram PH9837 = Napa 1522
Napa 1394 = fram hp-1
1064
Napa oil filter 1311 equivalent to Fram pH 7328
The Fram Filters cross reference guide for NAPA 1521 lists Fram PH43.
Fram CA3549
Fram PH7317
You will find Napa filters at Napa stores. Napa gold filters are made by Wix. Fram is available almost everywhere.
NAPA Gold 1358