diff --git a/go/common/l1_transaction.go b/go/common/l1_transaction.go
index 5af4ac1f6..1114a687f 100644
--- a/go/common/l1_transaction.go
+++ b/go/common/l1_transaction.go
@@ -20,18 +20,18 @@ const (
 	SetImportantContractsTx
 )
 
+// ProcessedL1Data is submitted to the enclave by the guardian
+type ProcessedL1Data struct {
+	BlockHeader *types.Header
+	Events      []L1Event
+}
+
 // L1Event represents a single event type and its associated transactions
 type L1Event struct {
 	Type uint8
 	Txs  []*L1TxData
 }
 
-// ProcessedL1Data is submitted to the enclave by the guardian
-type ProcessedL1Data struct {
-	BlockHeader *types.Header
-	Events      []L1Event // Changed from map to slice of L1Event
-}
-
 // L1TxData represents an L1 transaction that are relevant to us
 type L1TxData struct {
 	Transaction        *types.Transaction
@@ -51,7 +51,6 @@ func (tx *L1TxData) HasSequencerEnclaveID() bool {
 func (p *ProcessedL1Data) AddEvent(txType L1TxType, tx *L1TxData) {
 	eventType := uint8(txType)
 
-	// Find existing event group
 	for i := range p.Events {
 		if p.Events[i].Type != eventType {
 			continue
diff --git a/go/host/enclave/guardian.go b/go/host/enclave/guardian.go
index c9144e790..8b3251928 100644
--- a/go/host/enclave/guardian.go
+++ b/go/host/enclave/guardian.go
@@ -468,12 +468,6 @@ func (g *Guardian) submitL1Block(block *common.L1Block, isLatest bool) (bool, er
 		g.logger.Debug("Unable to submit block, enclave is busy processing data")
 		return false, nil
 	}
-	//receipts, err := g.sl.L1Repo().FetchObscuroReceipts(block)
-	//if err != nil {
-	//	g.submitDataLock.Unlock() // lock must be released before returning
-	//	return false, fmt.Errorf("could not fetch obscuro receipts for block=%s - %w", block.Hash(), err)
-	//}
-	//txsReceiptsAndBlobs, rollupTxs, contractAddressTxs := g.sl.L1Publisher().ExtractRelevantTenTransactions(block, receipts)
 	processedData, err := g.sl.L1Repo().ExtractTenTransactions(block)
 	if err != nil {
 		g.submitDataLock.Unlock() // lock must be released before returning
diff --git a/go/host/l1/blockrepository.go b/go/host/l1/blockrepository.go
index 5ae0a2dec..267c97d8e 100644
--- a/go/host/l1/blockrepository.go
+++ b/go/host/l1/blockrepository.go
@@ -161,12 +161,18 @@ func (r *Repository) ExtractTenTransactions(block *common.L1Block) (*common.Proc
 	}
 
 	for _, l := range logs {
+		if len(l.Topics) == 0 {
+            r.logger.Warn("Log has no topics", "txHash", l.TxHash)
+            continue
+        }
+
 		txData, err := r.createTransactionData(l.TxHash)
 		if err != nil {
 			r.logger.Error("Error creating transaction data", "txHash", l.TxHash, "error", err)
 			continue
 		}
 
+		// first topic is always the event signature
 		switch l.Topics[0] {
 		case crosschain.CrossChainEventID:
 			r.processCrossChainLogs(l, txData, processed)
@@ -323,19 +329,6 @@ func (r *Repository) FetchBlockByHeight(height *big.Int) (*types.Block, error) {
 	return r.ethClient.BlockByNumber(height)
 }
 
-// isObscuroTransaction will look at the 'to' address of the transaction, we are only interested in management contract and bridge transactions
-func (r *Repository) isObscuroTransaction(transaction *types.Transaction) bool {
-	var allAddresses []gethcommon.Address
-	allAddresses = append(allAddresses, r.contractAddresses[MgmtContract]...)
-	allAddresses = append(allAddresses, r.contractAddresses[MsgBus]...)
-	for _, address := range allAddresses {
-		if transaction.To() != nil && *transaction.To() == address {
-			return true
-		}
-	}
-	return false
-}
-
 // getEnclaveIdFromLog gets the enclave ID from the log topic
 func getEnclaveIdFromLog(log types.Log) (gethcommon.Address, error) {
 	if len(log.Topics) != 1 {
diff --git a/integration/ethereummock/mgmt_contract_lib.go b/integration/ethereummock/mgmt_contract_lib.go
index 2c29e6104..6c898131e 100644
--- a/integration/ethereummock/mgmt_contract_lib.go
+++ b/integration/ethereummock/mgmt_contract_lib.go
@@ -60,6 +60,9 @@ func (m *mockContractLib) GetContractAddr() *gethcommon.Address {
 func (m *mockContractLib) DecodeTx(tx *types.Transaction) ethadapter.L1Transaction {
 	// Do not decode erc20 transactions, this is the responsibility
 	// of the erc20 contract lib.
+	if tx.To() == nil {
+		println("HERE")
+	}
 	if tx.To().Hex() == depositTxAddr.Hex() {
 		return nil
 	}
diff --git a/integration/simulation/simulation_in_mem_test.go b/integration/simulation/simulation_in_mem_test.go
index 625efe824..052eaebf9 100644
--- a/integration/simulation/simulation_in_mem_test.go
+++ b/integration/simulation/simulation_in_mem_test.go
@@ -16,8 +16,6 @@ import (
 // Everything else is reported to this value. This number has to be adjusted in conjunction with the number of nodes. If it's too low,
 // the CPU usage will be very high during the simulation which might give inconclusive results.
 func TestInMemoryMonteCarloSimulation(t *testing.T) {
-	//FIXME temporarily disable
-	t.Skipf("skipping test until mocks are written")
 	setupSimTestLog("in-mem")
 
 	// todo (#718) - try increasing this back to 7 once faster-finality model is optimised