The gear box and rear axle are both 1954 (“X”). The car is a 1954 (“X” chassis number), but the engine is a 1953 (“W”). Take for example an SM 1500 roadster with chassis number 4AD3024 X, engine number 3046 W, gearbox number 3090 X and rear axle number 2957 X. Twin carburated cars have a ‘T’ in the number as in 4ADT. Total production = 11,950, Left Hand Drive cars have a ‘L’ prefix so the number would be L4AD. Please click 'Accept', as that is the way I am compensated by JA for my service to you.

The 8th digit of the serial number, which will be a letter (and typically the next to last digit) denotes the year of manufacture for units manufactured from the 1980s to the early 1990s: A 1980 I (not used) B 1981 J 1988. For Example: Serial 24-58637 24 + 50 1974. How do I tell the age of an Armstrong Air furnace or air conditioner from the serial number Wednesday, June 13, 2018. I hope this answer has been helpful to you. NOTE: From 1974 to present, the prefix number plus 50 will give you the year of manufacure. If it is in excellent condition, its current retail (replacement) value is approximately 500. The serial number is just behind the right front suspension, I am working on a drawing for ALL Singer’s to show the location of all the number. The serial number indicates that your Armstrong (Conn-Selmer) flute was built circa 1965. In your case, the serial number is 7 digits with no prefix. The letters following the chassis number as well as some of the unit numbers (eg the engine, gear box, rear axle, etc) indicate the year of manufacture on post war Singers. The prefix serial numbers you mentioned on Armstrong flutes are 2 digits, a dash, plus 5 more digits. Dating Singers and the wife will not be mad at you.

Armstrong serial number chart