I love the classic Ral Partha and Grenadier miniatures because they were among the first miniatures I owned, and one of my many projects is to recreate or convert some of these figures so that they are compatible with my 1/72 scale figures.
When I first started doing conversions, I was hesitant about taking my file and metal snips to old figures. My conservationist instincts told me that I would essentially be destroying something that was no longer in production, and what some might consider a work of art.
Then I got over it. Having figures sitting around and not being used is also a disservice to them, and despite what eBay listings would have you believe, the vast majority of these figures are not rare.
Here are some of the results of my efforts:
The Barbarian Hero (Ral Partha 01-009) is one of the early true 25mm figures, and can pretty much be used as is (although his head is rather large). The main issue I had with this particular miniature is the awkward pose. I modeled my conversion after the appearance of Frazetta's Conan the Adventurer.
A tooth necklace was made with Kneadatite, and his arms were repositioned. The scabbard was moved to the small of his back. Simple.
In many cases though, the old 25mm figures have the typical issues common to metal figures of being too chunky, having oversized heads, and oversized arms/hands. One such example is the Magic User from the Grenadier Wizards boxed set (Grenadier 2001).
I sculpted a new head and narrowed the torso a bit. An arm was added from a plastic figure, with the sleeve built up from Kneadatite. I also reduced the volume of the left sleeve, and added a dagger blade made from a flattened paperclip to his right hip.
Scale related modifications are typically not required for monsters, but I often alter the poses (particularly when I have multiple copies of the same monster).
The Stalking Kree-Ack from the Subterranean Terrors boxed set (Grenadier 2012) was a fairly simple conversion. I never really liked this miniatures because it always fell apart at the slightest touch. I don't think I've seen one of these figures that was assembled that didn't have the single supporting leg on the "waving" side that was not broken either.
I lowered the waving hand so that the creature looked less cheerful. I pinned, glued, and epoxied to hold all the pieces together. The patina on the converted Kree-Ack is actually quite nice. It's a bit of a shame to paint over it.
The Grenadier Dragon Turtle (Monster Manuscript Vol.II 1502, MM17) is a great figure, but I wasn't too fond of the "Hey Steve!" pose.
Grenadier metal from this period is often crystalline and brittle in nature, and I ended up snapping the neck when I tried to bend the head, so some pinning and sculpting was required to straighten the head so that it faced forward.