You probably know that is a GXV140 engine on it. Honda utilities' model names start with HUT, followed by the cutting width, followed by the alleged gross horsepower of the engine. So, if that mower is 21" and if the GXV140 (5.0 HP) is original, it would be called HUT215. Here is a dealer's advertisement for an HUT215:
[Linked Image]

The mower frame may not be Honda at all, or the mower may be an HUT216 or HUT21R or HUT19R that has been re-engined. Note that the mowers with R on the end (for "residential", meaning not for commercial use) instead of a power figure have the appalling OHC engines, so re-engining might be on the cards for those.

Someone else may recognise that base. If not you might try cleaning it up and posting some close-ups.

Last edited by grumpy; 11/01/13 09:53 AM. Reason: Add image