Probably, it’s a Morgan so anything’s possible… if you lift off the carpet on the parcel shelf behind the front seats you will see, possibly, a blanking plate which could be wood or aluminium. Not all Morgan’s had this so it may be you have to cut an access panel or access this through the tool tray. Unscrew the blanking plate if present and you should find the battery over the axle. Once you have the battery replaced I would suggest you connect cables from the battery through a hole through the board, easy to drill, so you don’t need to remove it every time and then you can connect a C Tek, or similar, charger to keep everything topped up. All Morgan's vary but mine is ok for a month or more without charging but I normally plug it in if I know it won’t be used for a week or more just to make sure the battery remains fully charged.