If it has 24" rear wheels then it's a Power King. 1973 was right around the change in body styles. The earlier style had outboard mounted headlights with an exposed pulley on the front of the engine. These tractors would not have the electric PTO clutch. If it's this older style then, yes, it came in a plain Jane model called the Standard which had hand brakes, no lights or electric start and no sheet metal over the drive train. The Deluxe model had all those nicities. Chances are you are looking at what I call the styled model. It would still be an Economy and the model would be a Power King as I stated. I could help you more if you could send me a picture. I also have a list of good parts sources that I could email you once I have your address.
Yes, they did indeed make a back hoe for these tractors. If you want to find one available, I hope you have lot's of time before you need it. They are in demand. I have one with a front end loader and it's a great machine.
Value for these tractors is all over the map literally. What sells for $1500 in my area may only sell for $500 as little as 100 miles away. the company was very territorial. PA (where I live) they are pretty plentiful and it's not hard to get parts for them still so, they command a higher price. I've paid as little as $100 for the 65 Jim Dandy that I restored and as much as $2500 for the 83 2414 that I mow with. What it all boils down to is, how bad do you want it. Here's some basic guidlines for adds or deducts. Once I see a picture I can give you a better idea of base price.
Add value for hydraulic lift
Add value for three point hitch
Add value for dual transmissions
Without knowing more about it, it sounds as though this machine may top out between $1500 to $1800 with the imnplements if it is in nice shape. Don't be afraid of it if the present owner says that the tractors gets stuck in gear. After so many years of use, this happens and I know an easy fix. Ask if it ever sat outside. If it did, it probably has water in the tranny. First thing you do is drain the fluid and fill with new.
Enough for now. Email me at firstname.lastname@example.org and I'll be glad to assist any way I can.