You can get that seat mounting bracket that goes over the floor pan for like $19 online. If you want the part number I can scrounge it up.
I would recommend flushing any/everything out from under it and then spraying everything nearby with rust converter paint on yours if you aren't planning on pulling it, gotta love how car cancer gets in between sheetmetal spotweld seams and then festers.
I'd like those part numbers if you come across them. My seat brackets have corroded pretty badly on my 2000. I'd like to pull the seats and brackets and try and find some leather xj or zj seats.