I've done some searching around but my problem seems to be a bit too specific. I'll try to keep it short, though.
A bit of background for context:
I've been working on an Adventure Map all the way back in 1.5.2. I've put probably a good 6 months of work into it (off and on, of course) so "starting from scratch" is kind of off the table. While the majority (probably 90% of blocks used) is vanilla, I've added some mods to for both a bit of variety in scenery and for their interesting mechanics in puzzles and such.
I've held off on updating because the main mod's (which inspired the map) creator decided to skipped 1.6. But I've kept track of the new commands Mojang has added as well as new mods being released and finally decided it was time to leave 1.5 behind. 1.7.10 looks to be the best supported at the moment, so that's what I've settled on.
What I didn't know is how differently Block IDs are handled. I knew there would absolutely be a few quirks to be fixed, but I hoped most of my work would transfer. At the moment, my only option appears to be to open the map in vanilla to strip all the mod blocks and start from there. That would be my absolute worst case scenario for this and I hope it can be avoided.
The Problem (TL;DR):
What would be the best way to transfer a modded map from 1.5.2 to 1.7.10 with respect to how Block IDs are handled between the two versions?
Is there a way to alter the block ids of a map with some external tool? I know MCEdit can Fill/Replace, but that would strip damage values, which some blocks use to the effect that MC uses it for stair directions and different colors of wool. I'm sure something could be done manually with NBTExplorer (that thing has saved my ass so many times...:D) but it's far too many blocks to do one by one like that. Some sort of command line batch program is what comes to mind. Hell, I know a bit of java. If someone can point me in the direction of some library that can open/modify MC maps, I can probably stumble my way through it.
Is there a way to manually set block ids in 1.7.10 to the effect that you use to have to do in mod config files previously? Not my preferred fix, seems a bit messy since each client would need this opposed to just my map. Plus I don't know if something like this is functionally possible with the new block id system.
I think that about sums it up. Thanks for reading and thank you very much in advance if you can spare a moment to help me out.
Well, it's been almost a week... So I'm assuming this is a bit to specific a problem. I've settled on trying my luck making a MCEdit filter (a python script) on my own. For future reference for anyone that stumbles on this topic with a similar problem you can find some examples here by "gentlegiantJGC".