I attempted to get info on the coach side of things via Fleetwood and was told due to the age there was nothing available. Do you know of any sources?The tag indicates you have a Chevrolet motorhome chassis, widely known as a "P30" chassis. Fortunately there is an excellent service manual still available at https://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf
Not just brake parts but is there a source for the coach side of the rig - any diagrams and guides etc. like for example the plumbing system and the electric side of things - the furnace, fridge etcFleetwood won't be any help but you should be able to find parts. I had to get my parking brake repaired about a year ago and the shop didn't have any problem finding parts for it. Other P30 parts seem to be a bit tricky I had to check salvage yards.
On the chassis you have received some good advice. Unfortunately, the Fleetwood RV of today is in no way connected to the Fleetwood RV that built your coach. The original Fleetwood RV was once the largest manufacturer of RVs of every description and type. They had over time swallowed up dozens of smaller companies but in 2009 the old Fleetwood company was disolved and sold off in pieces to various buyers. The REV Group bought the brandname and most of the motorhome brands & rights but they have little if any information about RVs built preveious to their ownership and can do nothing of help to owners of those RVs.Not just brake parts but is there a source for the coach side of the rig - any diagrams and guides etc. like for example the plumbing system and the electric side of things - the furnace, fridge etc
The issue is clearly that you don't want any of the supports to sink into the ground but exactly what you will need to use depends on the solidity of the gravel support. I think that if it were me I'd want something capable of holding all of the required weight. I'm no engineer, but I think that I'd want something at least 3'X3' under each jack that is strong and also non-slip.if everything that is supporting weight should be on plate steel or wood since I’m in gravel and if so how to determine what is best option and size Ex. How much bigger then the area the support structures footprint is.