Great Britain Help Please

Have a stock book with some older material - but not a good catalogue at hand. Any advice on what I have here?

What you have is two Queen Victoria halfpenny stamps S.G.48 (Scott#58) which were printed on around 15 plates. The plate number would dictate the value.
You have three Queen Victoria One Penny stamps S.G.43 (Scott#33) and they were printed on plated numbering from 71 to 225 with a few not used. Again the pate number would give and indication of value. As your stamps are in generally poor condition the value is greatly reduced because of that condition.
Plate numbers are printed on the sides of the stamps.

Hi 'CanadaStamp',
Of the two 1/2d reds (1858-1870) you have both shades: Rose-red and Lake in order from left to right. Both are Plate 6 and are worth £25 each in perfect used condition, so I'd value yours as worth £7 each at most. I think that that's around 10 Canadian Dollars each but it it probably worth checking the conversion to Canadian Dollars.
I can't seem to make out the Plate Numbers of the first and third Penny Reds due to heavy cancellations, but the first is definitely Plate Ninety something, which, depending on the plate that you do eventually determine, can be worth from £2.75 to £7 perfectly used. I think that the third is Plate 197, worth £11 perfectly used but I wouldn't take my word for it. Yet, the Middle Penny Red is certainly Plate 187, which is, unfortunately, only worth £2.75 perfectly used, which is a shame as it is in the best condition out of all five stamps and is the least valuable.
I hope my input was helpful,
James

All the stamps have faults ranging from pulled or trimmed perfs to tears at the corners. Realistically, at retail this is a CDN$15 lot for everything. A dealer isn't likely to buy it at wholesale for anything as the stamps are too common and faulty.

If you were to sell all five together, most of the overall value would be in those two halfpennies; if you do consider selling, either separately sell them online, or add more stamps and use the Penny Reds as space-fillers in a more valuable lot. Otherwise, they all make an attractive contribution to a collection of Victorian Britain

Sc#MH167

This is "Mint Never Hinged"
The cross hatching shows what seems dust on the plate, or damage from
previous owners?

I do not see this damage on my £1 or just twice on the 20p

My loupe cannot pick up if the damage is to the face of the stamp.
Any ideas? Curious.