Two comments:
1) Usually "too fast" isn't a problem. For that matter "slower than the originals" isn't *always* a problem either, as often parts that were faster than the minimum spec were used. Some of the better schematics indicate the minimum specified EPROM (or RAM) speed for the design. All that said, I usually don't sweat the speed very much, unless something doesn't work as expected.
2) The pinouts of the 27010 (JEDEC 1Mb EPROM) and the 27301 (non-JEDEC 1Mb EPROM) are the same except for 2 pins swapped. So an adapter can be made by stacking sockets, bending out legs, and soldering wire. Here's a diagram showing the two pinouts side by side with the wiring needed to make an adapter:
Have you tried dumping (reading) the data on the original EPROMs, using the 27010 setting? It won't damage them even if they are non-JEDEC type. If you get all the data, you know they are JEDEC type.