Singer sewing table

I'm not really sure where else to turn. I found this sewing table on a buy/sell/trade site. It seemed to be a decent price so I snatched it up ($40) and I'd like to know where I can find the serial number on it. There is a tag on the seat cushion, but I can't seem to find a serial number anywhere else on it. If anybody could help me I would greatly appreciate it. Pictures posted.