I just found this guy while surfing on the big internet. www.boxrec.com/list_bouts.php?human_id=24129&cat=boxer A total of 465 fights, and in 1936 he had 48 (!) fights. So todays fighters should maybe not be as busy as this guy, but maybe more than 1 fight a year like someone does should be great!
Here's what a 28 year old Wickwar looked like in his 458th bout, albeit a little out of his league against the 72-3-5 Eric Boon. https://www.britishpathe.com/video/boxing-eric-boon-v-len-wickwar-at-leicester