I'm using https://github.com/n00bsys0p/altcoin-seeder modified appropriately for my coin.

The changes are as follows;

bitcoin.cpp

Line 299
-  CService ip("litecointools.com", 9333, true);
+ CService ip("cryptodistributed.org", 9751, true);   // 9751 is the P2P Port for my Pfennig clone

combine.pl
Line 61 
- if ($addr =~ /\A(\d+)\.(\d+)\.(\d+)\.(\d+):9333/) {
+ if ($addr =~ /\A(\d+)\.(\d+)\.(\d+)\.(\d+):9751/) { 

db.h
Line 15
- #define REQUIRE_VERSION 70002
+#define REQUIRE_VERSION 70002  // Pfennig require version same as Bitcoin

Line 19
-  return testnet ? 0 : 470000;
+ return testnet ? 0 : 0;         // Set to 0 as genesis is only current checkpoint block

Line 122
-  if (clientVersion && clientVersion < 50000) { return 604800; }
+ if (clientVersion && clientVersion < 90201) { return 604800; }       // client version for Pfennig clone

main.cpp
Line 342
- static const string mainnet_seeds[] = {"dnsseed.litecointools.com", "dnsseed.litecoinpool.org", "dnsseed.ltc.xurious.com", ""};
- static const string testnet_seeds[] = {"testnet-seed.litecointools.com", ""};

+static const string mainnet_seeds[] = {"seed.cryptodistributed.org", ""};
+static const string testnet_seeds[] = {"testnet-seed.cryptodistributed.org", ""};

Line 351
-  db.Add(CService("kjy2eqzk4zwi5zd3.onion", 9333), true);
+ db.Add(CService("kjy2eqzk4zwi5zd3.onion", 9751), true); 

Line 380-383
- pchMessageStart[0] = 0xfc;
- pchMessageStart[1] = 0xc1;
- pchMessageStart[2] = 0xb7;
- pchMessageStart[3] = 0xdc;

+pchMessageStart[0] = 0x0b;
+pchMessageStart[1] = 0x11;
+pchMessageStart[2] = 0x09;
+pchMessageStart[3] = 0x07;   //testnet Pfennig magic numbers

protocol.cpp
+unsigned char pchMessageStart[4] = { 0xfb, 0xc0, 0xb6, 0xdb };
-unsigned char pchMessageStart[4] = { 0xf9, 0xbe, 0xb4, 0xd9 };   // mainnet Pfennig Magic number

protocol.h
- return testnet ? 19333 : 9333;
+ return testnet ? 19751 : 9751;