DB.
Before gathering up a bunch of loading for that rifle I would listen to guys like Martini that shoot these rifles and know them well.
The only input I will make regarding the Martini because I dont have one and I dont know what they have for a throat or chamber dimensions. But what I'm going to suggest to you is make a chamber cast of at least 1/2 of the chamber and a inch past the chamber end just past the throat. This will give you the dimensions you need for a proper PP or GG bullet for this rifle and have a mould made to fit your rifle's throat. Yes the cost will be more then a Lee but you will make up the difference on the brass you will save from not over working the necks.
Like I said I don't know the nature of the throat of the Martini but Martini said it had a fairly long free bore and I dont know if it is a cylinder type or tapered from the chamber case neck wall I call this a lead if it is tapered. If it is a straight cylinder type I call this free bore before the lead.
Once you have the cast and get your dimensions you select the paper thickness you can get most of and subtract the case wall thickness X2 (if the case neck wall is .011" you subtract .022" plus your paper thickness X4 and patch it to .002 under groove or bore diameter. I choose my paper thickness so two wraps will patch it to .001 over the depth of the grooves. Martininbelgain recommended patching to groove I would listen to that advice, because he shoots one.
The closest production mould you might be able to get might be NEI. http://www.neihandtools.com/catalog/index.html