I have found the following equipment to be essential to work effectively on vintage and modern gear. Here is a list of my favorite examples of good gear, with photos of my collection. Please note that the numbers do not (yet) correspond to the order of the photos.

Tube tester Capacitor tester LCR meter Crystal calibrator, multiple frequencies Frequency counter 150 MHz RF signal generator 150 KHz to VHF Precision RF signal generator with meter calibrated in uV Variable step attenuator Various small terminator resistors 50 Ohm, 75, etc MFJ-259 antenna analyzer Grid Dip Meter RF sweep generator Audio sine wave generator (with square wave output) Audio generator with sweep (for audio and low IF sweep) Audio Square wave generator Scope 20 MHz minimum Good scope probes Wideband VTVM (HP410) VTVM RCA Senior VoltOhmyst High Voltage Probe (50kV) for RF amplifiers RF probe for VTVM (DC) Demodulator probe for VTVM and scope VOM analog VOM digital RF & AF signal tracer Basic stereo amp and speakers with line input Power Supply dual tracking up to ±15 VDC @ 1 A Power Supply adjustable 50 Amp 13VDC with meters Digital Power supply ±12 & ±5 VDC (old computer supply) Variac with Isolation Transformer with meters High Voltage DC regulated Power Supply with bias and meters General purpose microphone to test transmitters Inexpensive Morse code Key to test transmitters RF dummy load 50 Ohm of sufficient wattage Digital Wattmeter (final test to power specs) Analog Wattmeter (easier to tune up) Speaker to test receivers General Coverage Shortwave Receiver (to look for spurious output) Decade Resistance Box (to provide resistors for testing) Box of capacitors to substitute for coupling and bypass caps Good temperature controlled Soldering Station 40 Watt Weller Soldering Gun 100/140 watt two step control Good quality 60/40 solder Rosin Solder flux Skotchbrite and sandpaper and files to clean for soldering BRIGHT flashlight Alignment tools Hand tools in good condition Small helper hands (test clip with heavy base) Small bench vise DE-OX-IT contact cleaner Alcohol Glues: Epoxy, Superglue, RTV (bathtub seal) Protoboard breadboarding system with wires Good magnifier system, self supporting Surface Mount Device tools Wish list items: Scope 150 MHz Spectrum Analyzer up to 200 MHz Distortion Analyzer HP334A Commercial 2 way radio service monitor (deviation test FM) High output RF generator (Tektronics, 5V into 50 Ohms)