There are some pics of home made adapters on google images. You might be able to sell a few of your mates adaptors. I think Toyota wanted a $100 ea when they had them.
Do they have a thread? I thought they were held in by 2 bolts. You need a dummy injector that can connect to the compression tester.
Toyota use to sell them but they seem to be out of stock or out of production
They also suit a 13BT