The plugs will not work. They are for late model applications, and have the wrong type of sealing surface to work with the 235 head.
As far as getting it running, it would be worthwile to to get it running before you start changing things, if only to make sure there aren't going to be other problems.
Which style oil bath do you have? There were a few different styles. The base model version, which simply has an oil wetted copper gauze as the filter media, can be easily converted by taking the od and id of the filter along woth the hight of the element and matching it up. Same applies to the larger styles, but you may have to do some trimming to make a paper element fit.
