Ramsey kits were never much good.
Your best bet is to salvage a TV modulator module from a dead VCR. You may need to build a small power amp if you want it to feed all the TVs in the house over the air. The Ramsey circuit you posted might do (but will need some mods). I'm a little hazy here with VHF linear "power" amps, but I think an emitter resistor of around 20 ohms, and a radio frequency choke from the collector to B+, and remove whatever was used to inject the video and audio into the collector.