Here some feedback on my side.
You basically got an entry level Raimundo guitar. As far as I can judge from the internet, you got it for 150 pounds while it sells new for 250 pounds.
As to Raimundo itself, this is certainly a good brand. Of course, these are "factory" made guitars. By factory this does not mean that they are not hand made, just that they are made with an industrial mindset, eg they are not produced by on single luthier but by a team of workers in a big warehouse, with the construction process of the guitar designed in a way to save working time spent on the guiar and also costs of material. That does not mean that the guitar is bad, but you cannot expect the level of care on the construction that you would have on a guitar costing 20 times that price. However, if you would have paid 20 times that price, you might not end up with a sound twenty times better...substantial prices increase only result into marginal increments in quality (however note you are at entry model level, so the curve is steeper there).
Personally, I have a Raimundo 148, which they market as a Concierto model, although this remains of course a study guitar. It sells at around 1000 euros. I bought it 20 years ago, meanwhile I moved to (much) more expensive guitars, so I can compare, and frankly the Raimundo is good. No regret. I bought it after having tried a few different ones in a Valencia shop, and in retrospect I can see I made a good choice. (Actually, a few years after I got another study guitar but from a french luthier, based on the insistence of my professor, and I did not find it really better than my Raimundo - in restrospect buying the luthier one was a waste of money)
Is it the best you can get from this price range? It´s hard to say. I have not tried the 104b so I cannot tell specifically how this one compares with other competitors within the same price range. I know the entry level of yamaha is very good for the price (the C40, I have one which I left with my step-family to avoid travelling with one guitar each time I go there). They can get it done very cheap using cheap labour in Phillipines (even cheaper than spanish workforce, also meaning the workers are not as nicely treated). You can also typically get good value for money with Esteve (I could test a few, and have a flamenco one the 8F), or - in a lower quality/price segment - with Prudencio Saez. Both from Valencia, like Raimundo.
In any event, for 150 pounds you should not have too much second thoughts, this is really cheap for a guitar. If the guitar has a nice sound and is playable (and I am pretty sure your 104b is playable, eg with not too high action, and also in tune), then you should be happy with it. For the next level of quality, you would need between 700 and 900 pounds. And the level after 1700 pounds. The best deals in my views are second hand luthier guitar- they sell for half the price new (if not one-third) and have the sound beautified by age. But first thing is to save the money.
For the fret markers just use some white stickers (cut for instance from a set of printable envelope labels), that will do the trick.
In a nutshell, I don´t think you´ve made a bad deal, if you enjoy playing the guitar that´s really all what you need, stop bothering about it, put the stickers for the playing comfort, and do enjoy practicing it without too much second thoughts.