Congratulations on the New-To-You camper!
As long as the original pump was a 12V demand pump, any 12V demand pump should do. BTW, demand pumps automatically shut off when the pre-set pressure is reached, (IE, all faucets are closed/off) and turn on when the pressure drops (IE, a faucet is turned on). This is the most common type of RV water pump. The
average pump is rated for around 2.8 gpm, with some of the better ones going up to 5.7 gmp. (I have the Shurflo Extreme 5.7...)
John