The number is pretty high so it could be a 82 aswell. Yeah its either really late 81 or an early 82. My 82 is only roughly about 200 more than your number. No one ( on here/on the net/us PE onwers) really knows what number the 81's ended at so to be 100% sure you gotta ring a suzuki dealer. Next problem is no all have this data, especially on the 82 models. If you contact this dealer they will be able to tell you exactly what yr the engine is.
http://www.kessnermotorcycles.com.au/ Not many eastern states had 82's so the dealers know nothing about them but i can tell you that the above dealer does have engine numbers for all PE's. On the net you will only find engine numbers up to 1980 because in 81 they went to the VIN number and are only identified by frame number, but there is a old book that some dealers have that says what the yr the engine numbers are still. When i got my 82 i knew it was a 82 but i wanted 100% proof so i rang up Kessner Suzuki and they looked in a book and told me 82 so that confirmed it for me. It probably wont matter too much to you as all 80-82 have same electrics anyway.
I remember you saying the rivets came out of the magnets on your old flywheel. PE magnets are glued in not riveted so sounds like you must of had a TS flywheel as they have riveted magnets.