The rectangular lamp you show is what the rear lamp assy in the cab models of the B3030 look like on some I have seen, some look just like the ones that come on the front of the B3030, which are similar at first glance to the L Grand lamps, but are not the same. The lamp assy (lamp head only)that you recieved is the current one used on several models as a dealer or customer add on; and I think Kubota has changed suppliers several times over the years, and it doesn't matter to Kubota that the units don't exactly match since any round pedestal/stud mount lamp head will work as long as it is within a given size, has both integral switch and a separate ground wire so either the stud or the second wire can be used as a ground as needed for all the different models over the years, and since all the smaller B series non cab models recommend adding only one rear lamp; it does not matter weather the actual lamp physically looks identical or not. I think your dealer either decided to mount it on the ROPS; and therefore had to make some brackets, or somehow wound up with just a lamp head (only) and used it with the fabricated brackets and between your salesperson (wholegoods), service manager, parts dept, and the tech who installed it decided to bill out the job by the kit number. The lamp you have is the one used in some kits, but it may or may not be the correct one for the B7335 kit. If you can't get the dealer to find you a picture, perhaps they can give you the contents of the kit as replacement parts; the lamp assy you have is listed as a 35305-3140-3 in the kit contents. These kits are designed for a very quick install, with no mods to the tractor; that is why they have several wiring extensions, and nice plated brackets. If you had all the tools laid out on a workbench; the lamp could be mounted in the Kubota specified location in 10-15 min total, so either the kit was wrong, an incomplete kit was used, or they decided to mount it somewhere other than the instructions specified. I would not be happy with that install; not so much whether or not the lamp is round or ractangular, but the sloppiness of the install.