I found the Mastermyr find too, but I seem to have entirely failed to spot the 3 Sledge Hammers. Returning to it I find 3 lovely large hammers of (69) 3.3kg, (70) 1.8kg, and (71) 1.5kg in size, these seem perfect for what I was thinking in my mind.
If you are serious about this project, I really do recommend that you invest in a copy of the primary report on the Mastermyr find:
The Mastermyr Find
Arwidsson and Berg
Like a lot of reports of this type, it had originally been published in extremely small number, and was a massive pain to find a copy of. There was enough demand that Norm Larson Books out of California approached and got permission from the authors to get a re-issue. Now the volume is easily available, typically for about $25 - $30.
The book has all the objects described in detail, plus both scaled three view drawings and photographs. You just could not ask for a better reference!
As you mention above, the range of the hammer heads includes some that I would say were fitted with longer handles to use a sledges. One of the problems is that of course none of the actually handles survived. (Those teams working on the total replica series of all the tools have said that with correct handles attached, you can not actually fit all the tools and pieces into the box. There are some questions about just what pieces where found just where in the original discovery. A bit of a mystery!)
Personally, I rarely use a hand hammer over 1 kg, my primary is 800 gm (echoes the 724 gm one in Mastermyr). For me its about control, not power. Remember as well that the primary aim of the VA bloomery process was to produce a very low carbon metal, desired for its relative ease of forging. The modern obsession with high carbon tool steels is just that - a modern concept.
On punching, I have long thought the object described as a 'Nail Making Iron' (# 86) might be more accurately described as a hot punching block. My logic here is that the holes are only very slightly tapered - and the shape might just as easily be an effect of the hot punching method used to make the holes in the first place. Hand forged nails are typically taped *square* cross section - not cylindrical.
There are also two objects in the box described as 'Underlays' (# 77 & 78). These are simple ring shapes of thick rectangular stock. Again these would function well to provide the dead air space required for completing the hot punch process.
I have used the method suggested of completing a hot punch by laying the working bar on top of a wood block. Huge amount of smoke (!) but it certainly works well.
There is actually one surviving anvil from the VA that does have a hole in it for hot punching. (I had this pointed out to me by Mark Pilgrim at L'Anse aux Meadows NHSC.) This artifact was included in the exhibit 'Full Circle, First Contact' which travelled Canada and the USA after 2000. The object is illustrated in that catalogue (page 21) with the caption : "Iron Anvil, Norway, c.1000 AD. Courtesy of Bergen Museum, University of Bergen, Norway." (you do have to look closely on the image below. The bottom edge of the hole can be seen just at the base of the horn.) I should warn you that there are not very many surviving artifacts from the Viking Age, and this is the only anvil with any kind of a hole in it I have ever noticed (and one of the few with a horn for that matter)
|Display case from 'Full Circle- First Contact'|