http://craftsmanlawn.com/Tractors-Riding-Lawnmowers/917.378492/

That might be as close as you'll get.

Some of them had a tab that had to be depressed to get the shroud off, even though the screws were out. Look carefully above the gas tank.

143986700 engine
These tanks are a bit of a pain. Once the fasteners are out, the tank snaps off hard. You will notice fasteners cleverly hidden behind the control above the carb. Below is a link for the Tecumseh service manual.

Here is a link that might be useful: Manual

Many thanks for the tips on how to get the top off, will let you know if I can find the clips. The Manual will be especially helpful on the rebuild. The Craftsman cross reference chart should be a help for the guys in the shop. Thanks again, MKC