I use these, in addition to locking fasteners. I fitted 2 pairs of the threaded inserts to each window to allow them to be locked in a closed or slightly open position.
These work for horizontally sliding 'Yorkshire' sashes too - I've one of these in my kitchen.
I use these, not old but I don't know if they had window locks back then
http://www.broughtons.com/product_details.php?p_id=5244&vlang_id=5239&sqs=1BQqVGMRHey8_A021jXNuTs2/nIR7uN9w/6MOEsg0GhegXb/fejc5eX6/Es7fQmsJlDOb6UGbrQ0M8xCoOFc_Ke1CNWXLNhWKkT8uWRvU1byhPBxL0BhFUgTie5X42P7kuoh6OyidQ9MLwcbklf1pHJDqJ9mzucY/3Zl5Tvl75Zeh7v9VF9odoFqYJ/rbXewXA/XkUaNQ20PfyyUl_yjBE9aTvjp8eLkKa_BDNIi2Qx5bbdbpIpecKCrDv/oEAzvR5ywlUrDwb96TXEq2biXmMi5BwibIJd_Q8VKUX2R/L6C/M58uh/7LNG7_7Vggbi8zUgMFbGk1E2RqBRe9DWi0y2/RC4svzrmhCUEYEY8a0lWZ9uXmcy5ar_JWqONrfNwGWtUU4Epiv4S/4oBOPLT7x9J4cTHJW/CmHRZjbVh/mdnx6qTs1fDg8FFV0KqB9s7kdYgnKp_BN9GwpTDMSLB0jeb1vxxFzfHH0JNdpvPA6Di5cooWfG9ShWJYE8vs5c4ZaKe0Mqxz9VRKMAjIeiHxk1OnnZOZG0pHELXkz9AvzhyMPF7j9uHE5ps9Cmg_r3w3BySJDTVsBv8pHqvo/LQW9_SuHLNpg8Jvo2MjkybLShdtJmGax899vLwAKgtkgD5CMQYiBRIOq4kASydQKnEE7sP49dz/rZuwz7XBfuVrYtBZ/3HwztdXZashnHkubyGEzGYzZujTYCTn5Pkv_jhLg==