Please help identify old English counterstamps

[brandm24]

This is one of several counterstamps struck on English coins presently offered in a lot at auction that I'm following. This one is struck on a near-smooth cartwheel penny...no date is visible.

I wasn't aware of the meaning of the diamond-shaped symbol so did an image search on Bing. Surprisingly, a near match came up that told me I had an English registry mark. Coded registry marks were assigned by the patent office beginning in 1842 to identify any number of products manufactured in various materials. I've included an image of "mine" (hopefully) and an example found on a Victorian ceramic memo pad.

While I now know the purpose of the stamp, I'm having difficulty deciphering the codes. Some are a little indistinct so I'm not completely sure of what they are. I've provided a link to a helpful site that explains the meaning of the marks but the charts are confusing to me. I was hoping someone could help me understand. Your help is much appreciated.
                                                                Dating_English_Registry_Marks

Many thanks,

Bruce

[malj1]

the first image is the early issue.

I indicates metal
I can't make out the letter at top perhaps B which is 1858
D = September
? = day

the second image is the later issue.

IV indicates ceramic
27 = day
9 = bundle
D = 1878
K = November

After this they used a Rgd No. for many years which was very useful.

I have a bookmark to this site which I find a little easier to use. See the side panel for other useful pages too.

[brandm24]

I also saw the top letter as a "B", but not completely sure about it. I also see "D" as the month (September). Hopefully, I'll win the lot so I can examine it more closely. Thanks for the link...it is a bit easier to interpret.

Bruce

[brandm24]

Here's another counterstamped coin from the same lot. This one is interesting but I have no idea what it's "saying." A company logo maybe.

Bruce

[brandm24]

These are the last two unidentified pieces in the lot of coppers I recently won at auction. They're probably not identifiable but thought I'd post them to see if anyone had any ideas. They look to be maker marks but that's all I can come with. The "arrow" coin looks to be dug and has no detail whatsoever, while the other one is on a 1770 English Penny.

Many thanks,

Bruce