Help with J Frame Serial Number

[Black_Sheep]

Just received an nice 3" blued, round butt Model 36 (no dash) with an odd serial number that's not showing up in the SCSW Appendix. I recall discussion of serial numbers with a "floating j", I think this one might fit the bill.

Serial # 380J4

Can anyone help determine it's DOB?

Thanks in advance...

 

[hotrod150]

Four digit floating j s/n -- looks like 1971-72.

 

[Black_Sheep]

Thank you...