I've inherited a vintage tandem. It looks as if it has been spray painted, and has no identifiers, etc remaining on the frame. The serial # on the bottom reads -459310. Any ideas on a make or model, and whether this is worth reparing? It needs a total re-work from the shredded tires up through the rusty chain and the dry-rotted seats and rusted handlebars...not a pretty picture if you get the drift.
The issues you've identified aren't terribly serious--however if they aren't a comprehensive listing of the issues (such as bad bearings, etc) then they may be understating the amount of work required.
The question of whether the make and model is "worth" repairing is largely up to you to decide. Being an unknown bike you should evaluate it on the value it has for you, rather than a broader market value.
The specific issues you've cited aren't terribly costly to resolve. You can purchase replacement tires, handlebars, and saddles from any good used parts shop for a fairly low price. A new chain is a small investment, and is a regular component to replace.
Overall though I presume your question is omitting some details. Photos and a more comprehensive listing of known issues will help better evaluate the potential to return the bike to a functional state.
Any functional tandem is worth a little bit of money, if only to someone who wants to put it in their front yard garden. Whether it's worth restoring to ride is harder to say.
Likely, from the sound of it, it's an old heavy steel frame, single speed bike with poor handling, and not worth anything to a serious cyclist.
But pictures would tell. Pictures should include the whole bike, some close-ups of the frame joints, some close-ups of the wheel hubs, and some close-ups of the cranks.
But, if the bearings are in good condition, restoring the items you've mentioned would be maybe $100-150. Whether it's worth that to you is the question.