It is difficult to estimate the ETA for OCR improvements. But I found a solution that works right away: Use ChineseSimplified (language=chs) as OCR language. This recognizes English as well and includes the Pound/Euro currency symbols.
My OCR.space test with Chinese as OCR language:
By comparison, here are my test results for Tesseract 4.0 LTSM:
Original image: The processing time for your original image was more than a minute(!), so I made the further tests just with the circle part.
Unmodified image (except cropped):
Reduced size by 50%
Inverted color:
