Looks good. The soft spot at the top of the post needs treating NOW before it gets worse. Eventually you will need a new post (probably at that time a complete side

) but that's many years away
For the time-being, scrape away any covering such as varnish, and ensure that the wood is dry. If any flakes out as you scrape, then it was rotten, and needed to come out anyway, but will spoil the look. Next stage, treat liberally with wood preservative - one that treats rot as well as being a preserver. For example, Cuprinol 5-Star. Now again ensure that the wood is absolutely dry before proceeding. Apply a wood hardener. These are effectively very thin 1-part resins that bond with the wood fibres. Cuprinol and Ronseal both offer similar products. Be careful, if it runs down the outside of the post, it will make a sticky mess and be difficult to remove. You want it IN the wood that is soft - a syringe and large bore needle might allow you to inject the hardener deeper. When that has cured, use a good quality wood filler to fill any holes or other blemishes, rub down, and stain to match. Finally, apply a good protective coat to the whole frame.
What top coating? Wel,, that's a whole new topic. Varnish looks good, but can lift and trap moisture. Danish Oil is easy, but is not a UV filter, so if kept outside, then the wood needs better treatment. Microporus coatings are good, but darker than varnish. Ask ten owners, and you'll get 12 different suggestions.
Have a look for the book "Morris Minor Traveller" by Ray Newell (available from the MMOC) with sections by Steve Foreman. It will tell you everything you need to know about Travellers.