John,
Yours is an interesting design, and the mechanism is feasible, but as John (Bogstandard) said, the first thing I noticed was the difficulties you would have sealing the valve down that deep slot. Once the slot is cut, you can do little with the surface finish inside and it is a finite width so it would be too difficult to get a good seal between the faces and the valve.
The only way I could see that working was if you made the cylinder in 2 separate pieces - the cylinder with a lapped port face, then a cover with the exhaust and inlet pipes, again lapped on the inside. This would have to be spring loaded equally around the valve (which would have to be lapped on both sides also). Again, as Bogs pointed out, you would need only 1 hole in the valve itself, which would oscillate between the inlet and exhaust ports.
In essence, all you would have done different from a standard oscillating engine is to immobilise the cylinder and create a separate valve that oscillates driven from another eccentric or crank.
Having said that, nobody will try to put you off, only help you, I still think it's quite a novel design and well done for grasping the concept and designing a mechanism that would work.
I would echo what Bogs said though, don't have any quarms about using ideas from other peoples engines, I've based all of my engines on other designs I've seen too, I haven't tried to re-invent the wheel, because that's too difficult!
I would recommend doing a simple oscillating engine first too, the link that Stew posted is one I designed recently specifically with beginners such as yourself in mind. I tried to make operations simple and keep parts and materials to a minimum. Doing an engine like this can instill a lot of confidence as well as give invaluable experience of the sorts of limits and fits you need to get engines to run before you go on to make one to your own design.
However, if you decide to try your own design straight off there are lots of people willing to help and offer advice so don't hesitate to ask!
Nick