I purchased this insulator off of eBay the other day. I thought it odd that the seller was calling it a number 36 so I emailed him and asked why. His reply "because that is what is embossed on the insulator" made me reach for the bid button. I had never seen this style with a No 36 embossed on the back. Neither is it listed in the price guide. The BROOKFIELD on the front is quite bold. But, as you can see, the No 36 is rather weak as it is on many CD 136 Brookfields.