Apart from the Macwester 27, which had considerably deeper  draft, and profiled keels, pretty well all twin keel yachts of the 60’s and 70’s were not brilliant performers going to windward. However, don’t be discouraged, there are some basic issues to remember in order to get the job done.

Don’t try pointing too high. 50 degrees if the water is reasonably flat, and accept 55 if it’s getting choppy.

Keep moving : steer your way over the crest to avoid being stopped by the bigger waves.

Keep some shape in the sails to be able to get some power to keep the speed up. Avoid sheeting in too tightly, or having the boom amidships, especially with the mizzensail, which will act like a wind vane and push the bow to windward.

Reduce sail (reef the main) in good time, to avoid heeling excessively, as leeway is increased considerably if not. When it really gets to blow, consider jib and mizzensail only

If you find that progress is really not good enough, don’t be too proud to use the cast iron 4 cylinder staysail at 1300 to 1500 rpm, and then you can sheet in and point up to the wind!

As Bob says there are ways of making the old girl move! I have a 1m bow sprit out front with a 130% genoa. It can improved windward to 40-45 degrees, but costs you more when entering a marina. The bow sprit also allows the anchor to be mounted on the sprit away front sail and a storm jib can be mounted on the front stay to form a slot. However, When not in uses I take the front stay back to the mast as it can get in the way when tacking. The mizzen is sometime useful when sailing, but it’s mast is very useful for mounting radar, GPS aerials and wind turbines etc.