I wouldn't. The transition from practicing on an upright (which typically have weaker actions and easier control over the sound, as there isn't a lot of it) to a baby grand, despite how small it may be, is never seamless.A grand's action is aligned horizontally as to allow the hammers to be aided by gravity. This allows for faster repeated notes, trills, etc. Learning to play on it and have the same outcome as with an upright can be a hard task.
42 years is not that old. You have a long way to go.A very high quality upright or even a very high quality spinet can be a very satisfying instrument (my sister has a superb spinet which is a joy to play, and I have an equally pleasant big upright) but... they have to be very high quality instruments. Otherwise the limitations of the action or dynamic range or both will limit you on most music later than Beethoven (and even on late Beethoven).You seem to indicate that you have room for a grand, in which case I would recommend sticking to a grand, although your might want to get a better one -- or a different one.
I wouldn't. The transition from practicing on an upright (which typically have weaker actions and easier control over the sound, as there isn't a lot of it) to a baby grand, despite how small it may be, is never seamless. Learning to play on it and have the same outcome as with an upright can be a hard task.
with your currency given in sterling, you're on the right side of the atlantic to have access to those fine vintage uprights. the older bechstein, bluethner, grotrian steinweg, steingraeber und soehne verticals are quite scarce on the left side, plus americans often prefer shiny new furniture over used. my guess would be the sales of new acoustic pianos have a different split on the opposite sides of the atlantic, higher percentage of grands in the u.s.a, and the vertical market is dominated by asian brands. many americans would have a sampling bias if they're not among the fortunate who've played top tier verticals, particularly the european makes you're considering (the 48-52 in. yamahas and kawais get praised quite a bit). when we were shopping for a used vertical a few months ago, would have been happy to look at european brands if any could be found in our budget range, but there was virtually nothing.
Some grands are quite horrible and/or horribly difficult to play. Some uprights are quite the opposite. Many of both are somewhere in the middle. I play so many of each in an average week I hardly even notice the instrument's shape any more, except as regards whether I need to look up or down at the score.
Congratulations on finding a piano you like.Making a soundboard that will let all the frequencies out properly is a craft that requires proper material, proper technique, and probably a lot of scrapped parts that fell apart once they were shaved thin.Pianos that have this clear tone, as the US made Acrosonics did, draw a premium even on the prices of the great console scrap-out going on now. It is a similar process to making a good sounding guitar or violin. Dull boring pianos with no highs or lows like the Y***** studio at my church, can still be sold new by attractive salespeople, but eventually the word will get around. Best of luck with your progress.