Any idea what the Lipseys 44sp Flat top serial numbers start

[Fowler]

I just put a 5 1/2" on layaway for a few days and was wondering how low in serial numbers this gun really is!?!

 

[chet15]

The first batch that came out were serial numbered from at least 520-16831 and upward. Everybody figured they began serial numbering where the 50th Anniversary .357 flattop left off (highest known 520-16828). But then about sixty guns in the 520-15462 to 520-15561 s/n range showed up which I suspect was a group of already numbered cylinder frames that were found at Ruger (without the .357 cylinder frame rollmark no less!) and were finally finished with .44 Special barrels and rollmarks.
Chet15