John. Looks to be a '53 onwards from the numbers. When the primary cover comes off, look for a date stamped next to the chain tensioner. Also a date stamp is sometimes found near the Pressure Relief Valve (PRV) under the dynamo. A brazed on lug for a prop stand was introduced in 1953, earlier frames don't have this.
If it has been standing for a while, don't just kick it over. Read the Forum posts "Barn Find Bikes" You can do internal damage to the oil pump without taking sensible precautions. You will need to drain off the oil from the sump, these engines are well known for draining the oil tank into the motor when left standing.
Original ignition is by magneto. No battery is needed for firing it up.
Arrange finance now.....and welcome to the Forum.
Swarfy.