Hmmm, that's pretty late and past the normal model year changeover serials. Are you sure it couldn't be a 1955 model?
(1955)
Date --------------- Serial #`s From ----------------- To
01/05 to 01/12 ------- P17601 ------------------ P21800
02/04 to 02/24 ------- P21801 ------------------ P34283
02/25 ------------------ P34284 ------------------ P37274
02/28 ------------------ P37275 ------------------ P40100
03/03 to 03/10 ------- P40101 ------------------ P53813
03/11 ------------------ P53814 ------------------ P56739
03/14 to 03/30 ------- P56740 ------------------ P88650
04/05 to 04/12 ------- P88651 ------------------ P97266
04/14 ------------------ P97267 ------------------ P99999
04/15 ------------------ R00001 ------------------ R01451
04/18 to 04/29 ------- R01452 ------------------ R35452