Soft top

[MOTORHEAD]

A few years ago I bought a used top with bows and windshield attaching channels from a member here on CC. The seller didn't know what Cobra it might fit, but the price was such that just the metal pieces were worth more than the asking price.
With some modification to the main bow, I found that it would fit into the ferrules of my Kirkham, but that main bow seemed to be too high, but at that position the top looked like it could be made to fit.
The w/s channel pieces came unattached from the top material, and eventually I noticed that on both halves was hand written with a paint pen "COB 140" The lettering was obviously old and barely readable, and was on the forward facing surface of the channels, which normally would have top material glued to it, covering the lettering.
Could this top be from an original ? I looked up the COB serial #'s in my registry, but COB Cobras all have 4 digit sn's, none with the last 3 #,s as hi as 140.
Possibly from an AC Ace ?
Any one have any thoughts/knowledge about this ??