I want to add doors to my RTV520. These are the fabric doors to keep out wind and rain/snow. The site I am looking at shows doors that are compatible with the RTV400. Nowhere can I find dimensions for the ROPS on the 400 and the 520. Kubota main site told me to go to my dealer for the info. My dealer looked and told me they had no dimensions for the ROPS in any of the manuels they had. I am hoping someone around here has a 400 and can tell me what the front to back and top to bottom measurements are on the roll over gage. Please help, thanks.