It's hard to say if the HF version will be good or not. I find most things from there either work great or break the first time you use it. There is a lot of companies that sell compression testers. Napa probably is a good bet. Probably a good chance they are all made in china. You can ask Napa, and if they are not. Buy it.
Snyder's Model A sells a 14mm to 18mm adapter to run 14mm plugs in a model a. You can buy one to use when you compression test your early ford.
Lastly, if budget is an issue. Autozone (probably others) loan tools for free. They charge a hold on your credit card till you bring it back and then they refund it.
Best of luck!
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