What type of 4-speed is in this? What engine?

If this is the 6-cyl English 4-speed (Dagenham) the shaft seals for this, and gaskets, are a hard find. Ask me how I know. Most shops can do very little with these because parts are so hard to find. I've seen a gasket kit, I think, on eBay, but they wanted more than I wanted to pay, so I made my own gaskets, which is easy to do. The shaft seals I addressed by sandwiching an o-ring between the seal and the shift lever before bolting those back on. There is a tail-shaft seal you can still get, but that is the only easy item to find on these. They are made of unobtainium. I had to buy 5 or 6 of these to get enough good parts to build one good transmission, though I probably have enough parts to build another. Once I sell my wagon, which has this transmission, these spare parts are going on eBay to pay for all of my future projects combined.

If a V8 4-speed you are in better luck and most good transmission shops in your area can deal with these. Parts are more plentiful. Maybe Dennis, who lives in Florida, knows a good transmission shop. Otherwise ask around some of the local car clubs, since they usually know who (locally) to use and who to avoid.