[gadget73]

Check the resistors with an ohm meter. Almost always, if a resistor fails it reads high. Check them in circuit, and as long as they show at or below their marked resistance, they're almost certainly fine. If one reads funny, pull one end and check again. If its more than 20% out of tolerance, replace it. I wouldn't bother bulk replacing all of them but you'll probably find a couple that are out of whack.

Also, there are some things in these that look like the old dogbone resistors. They're ceramic capacitors, and very seldom go bad. Don't worry about those.

The chassis probably has a few screws through the bottom, and it will slide out.

The oval cans are your IF transformers. Leave those alone, theres not likely to be anything of concern in there. Some American radios have capacitors built into the transformers that go bad, but I'm not aware of this being a problem on Euro radios.